Recent studies have shown that stress can substantially facilitate breast cancer metastasis,which can be reduced by nonselective β1/β2-adrenergic receptor(β1/β2-AR)blocker.However,several side effects were identif...Recent studies have shown that stress can substantially facilitate breast cancer metastasis,which can be reduced by nonselective β1/β2-adrenergic receptor(β1/β2-AR)blocker.However,several side effects were identified.Thus,it is extremely warranted to explore more effective and better-tolerated β2-AR blocker.Currently,we demonstrated that baicalin(BA),a major bioactive component of Scutellaria baicalensis Georgi,could significantly attenuate stress hormones especially epinephrine(Epi)-induced breast cancer cell migration and invasion in vitro.Mechanistically,we identified that β2-AR was a direct target of BA via the drug affinity responsive target stability(DARTS)combined with mass spectrum assay,and BA photoaffinity probe with pull-down assay,which was further confirmed by a couple of biophysical and biochemical assays.Furthermore,we demonstrated that BA could directly bind to the Phe193 and Phe-289 of β2-AR,subsequently inhibit cyclic adenosine monophosphate-protein kinase A-focal adhesion kinase(cAMP-PKA-FAK)pathway,and thus impede epithelial-mesenchymal transition(EMT),thereby hindering the metastatic progression of the chronic stress coupled with syngeneic and xenograft in vivo orthotopic and tail vein mouse model.These findings firstly identify BA as a potential b2-AR inhibitor in the treatment of stress-induced breast cancer metastasis.展开更多
We studied the activation of β2-adrenergic receptor（β2AR） by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics（MD） simulation. The simulation was done on the assumption that β...We studied the activation of β2-adrenergic receptor（β2AR） by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics（MD） simulation. The simulation was done on the assumption that β2AR was surrounded with explicit water and infinite lipid bilayer membrane at body temperature. So the result should be close to that under the physiological conditions. We calculated the structure of binding sites in β2AR for the three ac- tivators. We also simulated the change of the conformation ofβ2AR in the transmembrane regions（TMs）, in the mo- lecular switches, and in the conserved DRY（Aspartic acid, Arginine and Tyrosine） motif. This study provides detailed information concerning the structure ofβ2AR during activation process.展开更多
Objective: To scan single nucleotide polymorphism ( SNP ) in Chinese alpha-2Aadrenergic receptor (α_(2A)-AR) gene and study the effects of the SNP on the gene expression.Methods: The complete sequence of α_(2A)-AR g...Objective: To scan single nucleotide polymorphism ( SNP ) in Chinese alpha-2Aadrenergic receptor (α_(2A)-AR) gene and study the effects of the SNP on the gene expression.Methods: The complete sequence of α_(2A)-AR gene was analyzed with automated DNA sequencer to scanSNPs. Genomic DNA was extracted from whole blood and a 239 bp fragment containing the G/Cpolymorphism was amplified with PCR using a pair of. specific primers. PCR-RFLP was used to performthe genotyping of the SNP at the site-1 296 bp of the people in the North of China. Electrophoresismobility shift assay ( EMSA ) was used to study the binding of the 390 bp fragments (- 1 414-1 025bp) with G or C at the site-1 296 bp and nuclear extracts . Results: In our study, two SNPs werefound in α_(2A)-AR gene. Allele frequencies of the SNP at the site-1 296 bp were 0.61 and 0.39 forG and C , and the genotype frequencies were 0.34 , 0.54 and 0.13 for GG, GC and CC respectively fromthe people in the North of China. In the EMSA, a specific binding appeared in the complex ofnuclear extracts and DNA with C at-1 296 bp . Conclusion: Two SNPs exist in α_(2A)-AR gene from thepeople in the North of China , and DNA fragment with allele C of the SNP at the site-1 296 bp couldbind with a specific protein, which could influence the gene expression.展开更多
Objective： To investigate the effects of gene transfer of a β-adrenergic receptor（β-AR） kinase inhibitor（β ARIct） on pulmonary β2-adrenergic receptor and cAMP following β2-AR agonist treatment in asthmatic m...Objective： To investigate the effects of gene transfer of a β-adrenergic receptor（β-AR） kinase inhibitor（β ARIct） on pulmonary β2-adrenergic receptor and cAMP following β2-AR agonist treatment in asthmatic mice, and to analyze the relationship between the routes of gene delivery and the changes of β2AR and cAMP. Methods： BALB/c mice were sensitized and challenged by ovalbumin to establish the asthmatic model treated with βAR agonist （salbutamol injected intramuscularly）. The plasmid with the expression of βARKct was constructed and βARKct gene transfer was performed through intravenous injection or intratracheal instillation in asthmatic mice. The gene expression was measured with Western blot analysis, and the changes of pulmonary β-AR and cAMP evaluated by Radioimmunoassay. Results： The expression of tranfered βARKct gene was detectable in lungs and it was expressed more in the lungs of the mice receiving intratracheally plasmid than those receiving intravenously. The levels of βAR and cAMP were upregulated after using plasmid-βARKct to the asthmatic mice treated with βAR agonist. Conclusion： Our results indicated that there were down-regulation of βAR and cAMP in asthmatic mice treated with βAR agonist. Gene transfer of βARKct could inhibit the extent of the down-regulation of βAR and cAMP. The route of gene delivery could also affect the degree of up-regulation of βAR and cAMP. Gene transfer βARKct may provide a novel approach to the therapeutic strategy for asthma.展开更多
Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2...Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2DM.Various considerations can make selecting and switching between different GLP-1 RAs challenging.Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.展开更多
Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insu...Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels.However,this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells.Recent research has explored the potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)as a novel intervention to modify the disease course and delay the onset of T1D.GLP-1RAs are medications initially developed for treating type 2 diabetes.They exert their effects by enhancing glucose-dependent insulin secretion,suppressing glucagon secretion,and slowing gastric emptying.Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D.This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D,possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells.This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification,which should open new avenues for preventing and treating T1D,improving the quality of life and long-term outcomes for individuals at risk of T1D.展开更多
BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are associated with significant cardiovascular benefit in type 2 diabetes(T2D).However,GLP-1RA or SGL...BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are associated with significant cardiovascular benefit in type 2 diabetes(T2D).However,GLP-1RA or SGLT-2I alone may not improve some cardiovascular outcomes in patients with prior cardiovascular co-morbidities.AIM To explore whether combining GLP-1RA and SGLT-2I can achieve additional benefit in preventing cardiovascular diseases in T2D.METHODS The systematic review was conducted according to PRISMA recommendations.The protocol was registered on PROSPERO(ID:42022385007).A total of 107049 participants from eligible cardiovascular outcomes trials of GLP-1RA and SGLT-2I were included in network meta-regressions to estimate cardiovascular benefit of the combination treatment.Effect modification of prior myocardial infarction(MI)and heart failure(HF)was also explored to provide clinical insight as to when the INTRODUCTION The macro-and micro-vascular benefits of glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are independent of their glucose-lowering effects[1].In patients with type 2 diabetes(T2D),the major cardiovascular outcome trials(CVOT)showed that dipeptidyl peptidase-4 inhibitors(DPP-4I)did not improve cardiovascular outcomes[2],whereas cardiovascular benefit of GLP-1RA or SGLT-2I was significant[3,4].Further subgroup analyses indicated that the background cardiovascular risk should be considered when examining the cardiovascular outcomes of these newer glucose-lowering medications.For instance,prevention of major adverse cardiovascular events(MACE)was only seen in those patients with baseline atherosclerotic cardiovascular disease[3,4].Moreover,a series of CVOT conducted in patients with heart failure(HF)have demonstrated that(compared with placebo)SGLT-2I significantly reduced risk of hospitalization for HF or cardiovascular death,irrespective of their history of T2D[5-8].However,similar cardiovascular benefits were not observed in those with myocardial infarction(MI)[9,10].Cardiovascular co-morbidities are not only approximately twice as common but are also associated with dispropor-tionately worse cardiovascular outcomes in patients with T2D,compared to the general population[11].Therefore,it is of clinical importance to investigate whether the combination treatment of GLP-1RA and SGLT-2I could achieve greater cardiovascular benefit,particularly when considering patients with cardiovascular co-morbidities who may not gain sufficient cardiovascular protection from the monotherapies.This systematic review with multiple network meta-regressions was mainly aimed to explore whether combining GLP-1RA and SGLT-2I can provide additional cardiovascular benefit in T2D.Cardiovascular outcomes of these newer antidiabetic medications were also estimated under effect modification of prior cardiovascular diseases.This was to provide clinical insight as to when the combination treatment might be prioritized.展开更多
In this editorial,we examine a paper by Koizumi et al,on the role of peroxisome proliferator-activated receptor(PPAR)agonists in alcoholic liver disease(ALD).The study determined whether elafibranor protected the inte...In this editorial,we examine a paper by Koizumi et al,on the role of peroxisome proliferator-activated receptor(PPAR)agonists in alcoholic liver disease(ALD).The study determined whether elafibranor protected the intestinal barrier and reduced liver fibrosis in a mouse model of ALD.The study also underlines the role of PPARs in intestinal barrier function and lipid homeostasis,which are both affected by ALD.Effective therapies are necessary for ALD because it is a critical health issue that affects people worldwide.This editorial analyzes the possibility of PPAR agonists as treatments for ALD.As key factors of inflammation and metabolism,PPARs offer multiple methods for managing the complex etiology of ALD.We assess the abilities of PPARα,PPARγ,and PPARβ/δagonists to prevent steatosis,inflammation,and fibrosis due to liver diseases.Recent research carried out in preclinical and clinical settings has shown that PPAR agonists can reduce the severity of liver disease.This editorial discusses the data analyzed and the obstacles,advantages,and mechanisms of action of PPAR agonists for ALD.Further research is needed to understand the efficacy,safety,and mechanisms of PPAR agonists for treating ALD.展开更多
Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabo...Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production.Significant changes occur in myocardial metabolism in AF.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus(T2DM)and obesity.GLP-1RAs have also been shown to reduce oxidative stress,inflammation,autonomic nervous system modulation,and mitochondrial function.This article reviews the changes in metabolic characteristics in cardiomyocytes in AF.Although the clinical trial outcomes are unsatisfactory,the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors,lowering the incidence of AF.展开更多
Objective Recent studies have indicated potential anti-inflammatory effects of glucagon-like peptide-1 receptor agonists(GLP-1RAs)on asthma,which is often comorbid with type 2 diabetes mellitus(T2DM)and obesity.Theref...Objective Recent studies have indicated potential anti-inflammatory effects of glucagon-like peptide-1 receptor agonists(GLP-1RAs)on asthma,which is often comorbid with type 2 diabetes mellitus(T2DM)and obesity.Therefore,we conducted a meta-analysis to assess the association between the administration of glucagon-like peptide-1(GLP-1)receptor-based agonists and the incidence of asthma in patients with T2DM and/or obesity.Methods PubMed,Web of Science,Embase,the Cochrane Central Register of Controlled Trials,and Clinicaltrial.gov were systematically searched from inception to July 2023.Randomized controlled trials(RCTs)of GLP-1 receptor-based agonists(GLP-1RA,GLP-1 based dual and triple receptor agonist)with reports of asthma events were included.Outcomes were computed as risk ratios(RR)using a fixedeffects model.Results Overall,39 RCTs with a total of 85,755 participants were included.Compared to non-GLP-1 receptor-based agonist users,a trend of reduced risk of asthma was observed in patients with T2DM or obesity using GLP-1 receptor-based agonist treatments,although the difference was not statistically significant[RR=0.91,95%confidence interval(CI):0.68 to 1.24].Further Subgroup analyses indicated that the use of light-molecular-weight GLP-1RAs might be associated with a reduced the risk of asthma when compared with non-users(RR=0.65,95%CI:0.43 to 0.99,P=0.043).We also performed sensitivity analyses for participant characteristics,study design,drug structure,duration of action,and drug subtypes.However,no significant associations were observed.Conclusion Compared with non-users,a modest reduction in the incidence of asthma was observed in patients with T2DM or obesity using GLP-1 receptor-based agonist treatments.Further investigations are warranted to assess the association between GLP-1 receptor-based agonists and the risk of asthma.展开更多
The gut-liver axis plays a crucial role in the development and progression of metabolic dysfunction-associated steatotic liver disease(MASLD).Key metabolites,including lipopolysaccharides,short-chain fatty acids(SCFAs...The gut-liver axis plays a crucial role in the development and progression of metabolic dysfunction-associated steatotic liver disease(MASLD).Key metabolites,including lipopolysaccharides,short-chain fatty acids(SCFAs),bile acids,and beneficial gut bacteria such as Bifidobacterium and Lactobacillus,are pivotal in this process.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)show promise in managing MASLD by promoting weight loss,enhancing insulin secretion,and improving liver health.They restore gut-liver axis functionality,and their effects are amplified through dietary modifications and gut microbiometargeted therapies.Emerging research highlights the interplay between GLP-1 RAs and gut microbiota,indicating that the gut microbiome significantly influences therapeutic outcomes.Metabolites produced by gut bacteria,can stimulate glucagon-like peptide-1(GLP-1)secretion,further improving metabolic health.Integrating dietary interventions with GLP-1 RA treatment may enhance liver health by modulating the gut microbiota-SCFAs-GLP-1 pathway.Future research is needed to understand personalized effects,with prebiotics and probiotics offering treatment avenues for MASLD.展开更多
The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)is estimated at 32.4%,reflecting its growing clinical significance.MASLD,which includes MASLD and metabolic dysfunction-associate...The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)is estimated at 32.4%,reflecting its growing clinical significance.MASLD,which includes MASLD and metabolic dysfunction-associated steato-hepatitis(MASH)has been linked to increased metabolic,cardiovascular,and malignant morbidity.Progression into fibrotic stages of MASLD is also strongly associated with liver-related mortality.The past few years have seen a heightened focus on creating innovative therapeutic strategies for MASH management.GLP-1 receptor agonists(RA)have also emerged as a potential treatment option.Studies on GLP-1 agonists,such as liraglutide and semaglutide,have demonstrated efficacy in MASH management,albeit with limited histological improvement of fibrosis.However,recent investigations into GLP-1/GIP RA(tirzepatide)and Glucagon/GLP-1 RA(survodutide)have shown even more encouraging results,with higher rates of MASH resolution and fibrosis improvement.The tolerability of these medications due to their gastrointestinal side effects remains a major concern.Future research should focus on optimizing drug regimens,identifying patients most likely to benefit,and balancing efficacy with tolerability.The evolving landscape of MASH therapeutics suggests a bright future,with the potential for combination therapies to further enhance patient outcomes.展开更多
Recent studies have confirmed thatβ-adrenergic receptors(β-ARs)are expressed on the surface of osteoblasts and osteoclasts,and that the sympathetic nervous system can regulate bone metabolism by activating them.β-A...Recent studies have confirmed thatβ-adrenergic receptors(β-ARs)are expressed on the surface of osteoblasts and osteoclasts,and that the sympathetic nervous system can regulate bone metabolism by activating them.β-AR blockers(BBs)are commonly used in the treatment of cardiovascular diseases in the elderly.It is important to investigate whether BBs have a beneficial effect on bone metabolism in the treatment of cardiovascular diseases,so as to expand their clinical application.This article reviews the effects of BB on bone metabolism and the progress of clinical research.展开更多
Glucagon-like peptide receptor agonists(GLP-1RA)are used to treat type 2 diabetes mellitus and,more recently,have garnered attention for their effect-iveness in promoting weight loss.They have been associated with sev...Glucagon-like peptide receptor agonists(GLP-1RA)are used to treat type 2 diabetes mellitus and,more recently,have garnered attention for their effect-iveness in promoting weight loss.They have been associated with several gastrointestinal adverse effects,including nausea and vomiting.These side effects are presumed to be due to increased residual gastric contents.Given the potential risk of aspiration and based on limited data,the American Society of Anesthesi-ologists updated the guidelines concerning the preoperative management of patients on GLP-1RA in 2023.They included the duration of mandated cessation of GLP-1RA before sedation and usage of“full stomach”precautions if these medications were not appropriately held before the procedure.This has led to additional challenges,such as extended waiting time,higher costs,and increased risk for patients.In this editorial,we review the current societal guidelines,clinical practice,and future directions regarding the usage of GLP-1RA in patients undergoing an endoscopic procedure.展开更多
Metabolic dysfunction-associated steatotic liver disease(MASLD)has become the most common chronic liver disease worldwide,paralleling the rising pandemic of obesity and type 2 diabetes.Due to the growing global health...Metabolic dysfunction-associated steatotic liver disease(MASLD)has become the most common chronic liver disease worldwide,paralleling the rising pandemic of obesity and type 2 diabetes.Due to the growing global health burden and com-plex pathogenesis of MASLD,a multifaceted and innovative therapeutic approach is needed.Incretin receptor agonists,which were initially developed for diabetes management,have emerged as promising candidates for MASLD treatment.This review describes the pathophysiological mechanisms and action sites of three major classes of incretin/glucagon receptor agonists:glucagon-like peptide-1 receptor agonists,glucose-dependent insulinotropic polypeptide receptor agonists,and glucagon receptor agonists.Incretins and glucagon directly or indirectly impact various organs,including the liver,brain,pancreas,gastro-intestinal tract,and adipose tissue.Thus,these agents significantly improve glycemic control and weight management and mitigate MASLD pathogenesis.Importantly,this study provides a summary of clinical trials analyzing the effect-iveness and safety of incretin receptor agonists in MASLD management and provides an in-depth analysis highlighting their beneficial effects on improving liver function,hepatic steatosis,and intrahepatic inflammation.There are emerging challenges associated with the use of these medications in the real world,particularly adverse events,drug-drug interactions,and barriers to access,which are discussed in detail.Additionally,this review highlights the evolving role of incretin receptor agonists in MASLD management and suggests future research directions.展开更多
This editorial takes a deeper look at the insights provided by Soresi and Giannitrapani,which examined the therapeutic potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for metabolic dysfunction-associat...This editorial takes a deeper look at the insights provided by Soresi and Giannitrapani,which examined the therapeutic potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for metabolic dysfunction-associated fatty liver disease.We provide supplementary insights to their research,highlighting the broader systemic implications of GLP-1RAs,synthesizing the current understanding of their mechanisms and the trajectory of research in this field.GLP-1RAs are revolutionizing the treatment of type 2 diabetes mellitus and beyond.Beyond glycemic control,GLP-1RAs demonstrate cardiovascular and renal protective effects,offering potential in managing diabetic kidney disease alongside renin–angiotensin–aldosterone system inhibitors.Their role in bone metabolism hints at benefits for diabetic osteoporosis,while the neuroprotective properties of GLP-1RAs show promise in Alzheimer's disease treatment by modulating neuronal insulin signaling.Additionally,they improve hormonal and metabolic profiles in polycystic ovary syndrome.This editorial highlights the multifaceted mechanisms of GLP-1RAs,emphasizing the need for ongoing research to fully realize their therapeutic potential across a range of multisystemic diseases.展开更多
Background: The objective of this study was to compare and analyze the variations in clinical indices before and after treatment of type 2 mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) that we...Background: The objective of this study was to compare and analyze the variations in clinical indices before and after treatment of type 2 mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) that were treated with glucagon-like peptide 1 receptor agonists (GLP-1RAs). Methods: The electronic medical record system was utilized to search for a total of 16 patients with type 2 diabetes complicated by NAFLD who were hospitalized at the First Affiliated Hospital of Yangtze University from October 2022 to April 2023 and treated with GLP-1RA for the first time. The clinical indices were compared before and after 12 weeks of treatment with GLP-1RA. Results: The liver-spleen CT ratio (L/S), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) in all patients treated with GLP-1RA after 12 weeks were significantly different (P 0.05). The patients were categorized into two groups based on the types of GLP-1RAs. The changes in L/S, TC, TG, and LDL-C in the long-acting group after treatment were statistically significant (P Conclusions: GLP-1RAs can improve liver function, regulate lipid metabolism, and reduce the severity of fatty liver in patients with T2DM complicated by NAFLD, which demonstrates the importance of clinical applications.展开更多
Abscisic acid(ABA),a plant hormone,is crucial for regulating various physiological and developmental processes in plants,including adaptation to biotic and abiotic stresses.Recent advancements have significantly contr...Abscisic acid(ABA),a plant hormone,is crucial for regulating various physiological and developmental processes in plants,including adaptation to biotic and abiotic stresses.Recent advancements have significantly contributed to our understanding of ABA's biosynthetic pathway,transport,signaling pathway,and metabolism.To overcome the limitations of natural ABA,scientists have developed broad-spectrum and highly active agonists of ABA receptors.However,the practical application of these receptor agonists as agrochemicals still faces several challenges.On the other hand,some ABA antagonists have also been developed to differentiate the functional differences among various receptors more accurately.This can help design ABA agonists that can selectively activate specific physiological responses,thereby eliminating the undesired physiological effects induced by ABA.This paper aims to provide a comprehensive overview of the current ABA receptor agonists and antagonists to assist in developing novel ABA functional analogs with improved efficacy and simpler chemical structures that are suitable for agricultural applications.展开更多
Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending co...Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction （MI） and [Ca^2＋]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2＋]i induced by isoproterenol in normal ventricular myocytes （P 〉 0.05）, ICI118, 551 only significantly attenuated the rise of [Ca^2＋]i induced by isoproterenol at four weeks and eight weeks after MI （24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01）. Atenolol had suppressive effects only in the control group and the post-MI group of two weeks （P 〈 0.05）, and propranolol had suppressive effects in the control and all the three post-MI groups （P 〈 0.01）. Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2＋ overload initiated by sympathetic stimulation after MI.展开更多
In the present study,selective β1-adrenergic receptor antagonist CGP20712A and selective β2-adrenergic receptor antagonist ICI 118551 were administered to isolated cardiomyocytes from young （4-6 months）,aged （18-...In the present study,selective β1-adrenergic receptor antagonist CGP20712A and selective β2-adrenergic receptor antagonist ICI 118551 were administered to isolated cardiomyocytes from young （4-6 months）,aged （18-20 months）,and clonidine-pretreated aged （18-20 months） Sprague-Dawley rats.Cardiomyocyte contraction amplitude was measured to assess cardiomyocyte response to the β-adrenergic receptor agonist,isoprenaline.CGP20712A reduced cardiomyocyte contraction amplitude in young and aged groups and significantly reduced contraction amplitude in cells from young rats.ICI 118551 had no effect on cardiomyocyte contraction amplitude in young rats,but significantly decreased contraction amplitude in the aged groups,in particular in the clonidine-pretreated aged rats.Results demonstrated that reduced central sympathetic tone improved cardiomyocyte contraction in aged rats by improving the response of β2-adrenergic receptor to isoprenaline.展开更多
基金supported by the Matching Grant of National Natural Science Foundation of China from Nanjing University of Chinese Medicine(Grant Nos.:NZY81903857,and NZY81703765)the National Natural Science Foundation of China(Grant No.:21877062)+1 种基金the Opening Project of Chinese Materia Medica FirstClass Discipline of Nanjing University of Chinese Medicine(Grant No.:2020YLXK020)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant Nos.:SJCX21_0707,KYCX21_1772,and KYCX22_2039).
文摘Recent studies have shown that stress can substantially facilitate breast cancer metastasis,which can be reduced by nonselective β1/β2-adrenergic receptor(β1/β2-AR)blocker.However,several side effects were identified.Thus,it is extremely warranted to explore more effective and better-tolerated β2-AR blocker.Currently,we demonstrated that baicalin(BA),a major bioactive component of Scutellaria baicalensis Georgi,could significantly attenuate stress hormones especially epinephrine(Epi)-induced breast cancer cell migration and invasion in vitro.Mechanistically,we identified that β2-AR was a direct target of BA via the drug affinity responsive target stability(DARTS)combined with mass spectrum assay,and BA photoaffinity probe with pull-down assay,which was further confirmed by a couple of biophysical and biochemical assays.Furthermore,we demonstrated that BA could directly bind to the Phe193 and Phe-289 of β2-AR,subsequently inhibit cyclic adenosine monophosphate-protein kinase A-focal adhesion kinase(cAMP-PKA-FAK)pathway,and thus impede epithelial-mesenchymal transition(EMT),thereby hindering the metastatic progression of the chronic stress coupled with syngeneic and xenograft in vivo orthotopic and tail vein mouse model.These findings firstly identify BA as a potential b2-AR inhibitor in the treatment of stress-induced breast cancer metastasis.
基金Supported by the Young and Middle-Aged Scientists Research Awards Foundation of Shangdong Province,China(No.BS2011SW002)the Research Foundation for Advanced Talents of Ludong University,China(No.LY2011017)
文摘We studied the activation of β2-adrenergic receptor（β2AR） by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics（MD） simulation. The simulation was done on the assumption that β2AR was surrounded with explicit water and infinite lipid bilayer membrane at body temperature. So the result should be close to that under the physiological conditions. We calculated the structure of binding sites in β2AR for the three ac- tivators. We also simulated the change of the conformation ofβ2AR in the transmembrane regions（TMs）, in the mo- lecular switches, and in the conserved DRY（Aspartic acid, Arginine and Tyrosine） motif. This study provides detailed information concerning the structure ofβ2AR during activation process.
文摘Objective: To scan single nucleotide polymorphism ( SNP ) in Chinese alpha-2Aadrenergic receptor (α_(2A)-AR) gene and study the effects of the SNP on the gene expression.Methods: The complete sequence of α_(2A)-AR gene was analyzed with automated DNA sequencer to scanSNPs. Genomic DNA was extracted from whole blood and a 239 bp fragment containing the G/Cpolymorphism was amplified with PCR using a pair of. specific primers. PCR-RFLP was used to performthe genotyping of the SNP at the site-1 296 bp of the people in the North of China. Electrophoresismobility shift assay ( EMSA ) was used to study the binding of the 390 bp fragments (- 1 414-1 025bp) with G or C at the site-1 296 bp and nuclear extracts . Results: In our study, two SNPs werefound in α_(2A)-AR gene. Allele frequencies of the SNP at the site-1 296 bp were 0.61 and 0.39 forG and C , and the genotype frequencies were 0.34 , 0.54 and 0.13 for GG, GC and CC respectively fromthe people in the North of China. In the EMSA, a specific binding appeared in the complex ofnuclear extracts and DNA with C at-1 296 bp . Conclusion: Two SNPs exist in α_(2A)-AR gene from thepeople in the North of China , and DNA fragment with allele C of the SNP at the site-1 296 bp couldbind with a specific protein, which could influence the gene expression.
文摘Objective： To investigate the effects of gene transfer of a β-adrenergic receptor（β-AR） kinase inhibitor（β ARIct） on pulmonary β2-adrenergic receptor and cAMP following β2-AR agonist treatment in asthmatic mice, and to analyze the relationship between the routes of gene delivery and the changes of β2AR and cAMP. Methods： BALB/c mice were sensitized and challenged by ovalbumin to establish the asthmatic model treated with βAR agonist （salbutamol injected intramuscularly）. The plasmid with the expression of βARKct was constructed and βARKct gene transfer was performed through intravenous injection or intratracheal instillation in asthmatic mice. The gene expression was measured with Western blot analysis, and the changes of pulmonary β-AR and cAMP evaluated by Radioimmunoassay. Results： The expression of tranfered βARKct gene was detectable in lungs and it was expressed more in the lungs of the mice receiving intratracheally plasmid than those receiving intravenously. The levels of βAR and cAMP were upregulated after using plasmid-βARKct to the asthmatic mice treated with βAR agonist. Conclusion： Our results indicated that there were down-regulation of βAR and cAMP in asthmatic mice treated with βAR agonist. Gene transfer of βARKct could inhibit the extent of the down-regulation of βAR and cAMP. The route of gene delivery could also affect the degree of up-regulation of βAR and cAMP. Gene transfer βARKct may provide a novel approach to the therapeutic strategy for asthma.
文摘Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2DM.Various considerations can make selecting and switching between different GLP-1 RAs challenging.Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.
文摘Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels.However,this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells.Recent research has explored the potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)as a novel intervention to modify the disease course and delay the onset of T1D.GLP-1RAs are medications initially developed for treating type 2 diabetes.They exert their effects by enhancing glucose-dependent insulin secretion,suppressing glucagon secretion,and slowing gastric emptying.Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D.This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D,possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells.This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification,which should open new avenues for preventing and treating T1D,improving the quality of life and long-term outcomes for individuals at risk of T1D.
基金Supported by China Scholarship Council,No.202006920018Key Talent Program for Medical Applications of Nuclear Technology,No.XKTJ-HRC2021007+2 种基金the Second Affiliated Hospital of Soochow University,No.SDFEYBS1815 and No.SDFEYBS2008National Natural Science Foundation of China,No.82170831The Jiangsu Innovation&Career Fund for PhD 2019.
文摘BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are associated with significant cardiovascular benefit in type 2 diabetes(T2D).However,GLP-1RA or SGLT-2I alone may not improve some cardiovascular outcomes in patients with prior cardiovascular co-morbidities.AIM To explore whether combining GLP-1RA and SGLT-2I can achieve additional benefit in preventing cardiovascular diseases in T2D.METHODS The systematic review was conducted according to PRISMA recommendations.The protocol was registered on PROSPERO(ID:42022385007).A total of 107049 participants from eligible cardiovascular outcomes trials of GLP-1RA and SGLT-2I were included in network meta-regressions to estimate cardiovascular benefit of the combination treatment.Effect modification of prior myocardial infarction(MI)and heart failure(HF)was also explored to provide clinical insight as to when the INTRODUCTION The macro-and micro-vascular benefits of glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are independent of their glucose-lowering effects[1].In patients with type 2 diabetes(T2D),the major cardiovascular outcome trials(CVOT)showed that dipeptidyl peptidase-4 inhibitors(DPP-4I)did not improve cardiovascular outcomes[2],whereas cardiovascular benefit of GLP-1RA or SGLT-2I was significant[3,4].Further subgroup analyses indicated that the background cardiovascular risk should be considered when examining the cardiovascular outcomes of these newer glucose-lowering medications.For instance,prevention of major adverse cardiovascular events(MACE)was only seen in those patients with baseline atherosclerotic cardiovascular disease[3,4].Moreover,a series of CVOT conducted in patients with heart failure(HF)have demonstrated that(compared with placebo)SGLT-2I significantly reduced risk of hospitalization for HF or cardiovascular death,irrespective of their history of T2D[5-8].However,similar cardiovascular benefits were not observed in those with myocardial infarction(MI)[9,10].Cardiovascular co-morbidities are not only approximately twice as common but are also associated with dispropor-tionately worse cardiovascular outcomes in patients with T2D,compared to the general population[11].Therefore,it is of clinical importance to investigate whether the combination treatment of GLP-1RA and SGLT-2I could achieve greater cardiovascular benefit,particularly when considering patients with cardiovascular co-morbidities who may not gain sufficient cardiovascular protection from the monotherapies.This systematic review with multiple network meta-regressions was mainly aimed to explore whether combining GLP-1RA and SGLT-2I can provide additional cardiovascular benefit in T2D.Cardiovascular outcomes of these newer antidiabetic medications were also estimated under effect modification of prior cardiovascular diseases.This was to provide clinical insight as to when the combination treatment might be prioritized.
文摘In this editorial,we examine a paper by Koizumi et al,on the role of peroxisome proliferator-activated receptor(PPAR)agonists in alcoholic liver disease(ALD).The study determined whether elafibranor protected the intestinal barrier and reduced liver fibrosis in a mouse model of ALD.The study also underlines the role of PPARs in intestinal barrier function and lipid homeostasis,which are both affected by ALD.Effective therapies are necessary for ALD because it is a critical health issue that affects people worldwide.This editorial analyzes the possibility of PPAR agonists as treatments for ALD.As key factors of inflammation and metabolism,PPARs offer multiple methods for managing the complex etiology of ALD.We assess the abilities of PPARα,PPARγ,and PPARβ/δagonists to prevent steatosis,inflammation,and fibrosis due to liver diseases.Recent research carried out in preclinical and clinical settings has shown that PPAR agonists can reduce the severity of liver disease.This editorial discusses the data analyzed and the obstacles,advantages,and mechanisms of action of PPAR agonists for ALD.Further research is needed to understand the efficacy,safety,and mechanisms of PPAR agonists for treating ALD.
基金supported by the Clinical Medical Technology Innovation Project of Hunan Science and Technology Agency,China(Project No.:2021SK53519).
文摘Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production.Significant changes occur in myocardial metabolism in AF.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus(T2DM)and obesity.GLP-1RAs have also been shown to reduce oxidative stress,inflammation,autonomic nervous system modulation,and mitochondrial function.This article reviews the changes in metabolic characteristics in cardiomyocytes in AF.Although the clinical trial outcomes are unsatisfactory,the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors,lowering the incidence of AF.
基金supported by The Beijing Natural Science Foundation[No.7202216]the National Natural Science Foundation of China[No.81970698 and No.81970708].
文摘Objective Recent studies have indicated potential anti-inflammatory effects of glucagon-like peptide-1 receptor agonists(GLP-1RAs)on asthma,which is often comorbid with type 2 diabetes mellitus(T2DM)and obesity.Therefore,we conducted a meta-analysis to assess the association between the administration of glucagon-like peptide-1(GLP-1)receptor-based agonists and the incidence of asthma in patients with T2DM and/or obesity.Methods PubMed,Web of Science,Embase,the Cochrane Central Register of Controlled Trials,and Clinicaltrial.gov were systematically searched from inception to July 2023.Randomized controlled trials(RCTs)of GLP-1 receptor-based agonists(GLP-1RA,GLP-1 based dual and triple receptor agonist)with reports of asthma events were included.Outcomes were computed as risk ratios(RR)using a fixedeffects model.Results Overall,39 RCTs with a total of 85,755 participants were included.Compared to non-GLP-1 receptor-based agonist users,a trend of reduced risk of asthma was observed in patients with T2DM or obesity using GLP-1 receptor-based agonist treatments,although the difference was not statistically significant[RR=0.91,95%confidence interval(CI):0.68 to 1.24].Further Subgroup analyses indicated that the use of light-molecular-weight GLP-1RAs might be associated with a reduced the risk of asthma when compared with non-users(RR=0.65,95%CI:0.43 to 0.99,P=0.043).We also performed sensitivity analyses for participant characteristics,study design,drug structure,duration of action,and drug subtypes.However,no significant associations were observed.Conclusion Compared with non-users,a modest reduction in the incidence of asthma was observed in patients with T2DM or obesity using GLP-1 receptor-based agonist treatments.Further investigations are warranted to assess the association between GLP-1 receptor-based agonists and the risk of asthma.
文摘The gut-liver axis plays a crucial role in the development and progression of metabolic dysfunction-associated steatotic liver disease(MASLD).Key metabolites,including lipopolysaccharides,short-chain fatty acids(SCFAs),bile acids,and beneficial gut bacteria such as Bifidobacterium and Lactobacillus,are pivotal in this process.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)show promise in managing MASLD by promoting weight loss,enhancing insulin secretion,and improving liver health.They restore gut-liver axis functionality,and their effects are amplified through dietary modifications and gut microbiometargeted therapies.Emerging research highlights the interplay between GLP-1 RAs and gut microbiota,indicating that the gut microbiome significantly influences therapeutic outcomes.Metabolites produced by gut bacteria,can stimulate glucagon-like peptide-1(GLP-1)secretion,further improving metabolic health.Integrating dietary interventions with GLP-1 RA treatment may enhance liver health by modulating the gut microbiota-SCFAs-GLP-1 pathway.Future research is needed to understand personalized effects,with prebiotics and probiotics offering treatment avenues for MASLD.
文摘The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)is estimated at 32.4%,reflecting its growing clinical significance.MASLD,which includes MASLD and metabolic dysfunction-associated steato-hepatitis(MASH)has been linked to increased metabolic,cardiovascular,and malignant morbidity.Progression into fibrotic stages of MASLD is also strongly associated with liver-related mortality.The past few years have seen a heightened focus on creating innovative therapeutic strategies for MASH management.GLP-1 receptor agonists(RA)have also emerged as a potential treatment option.Studies on GLP-1 agonists,such as liraglutide and semaglutide,have demonstrated efficacy in MASH management,albeit with limited histological improvement of fibrosis.However,recent investigations into GLP-1/GIP RA(tirzepatide)and Glucagon/GLP-1 RA(survodutide)have shown even more encouraging results,with higher rates of MASH resolution and fibrosis improvement.The tolerability of these medications due to their gastrointestinal side effects remains a major concern.Future research should focus on optimizing drug regimens,identifying patients most likely to benefit,and balancing efficacy with tolerability.The evolving landscape of MASH therapeutics suggests a bright future,with the potential for combination therapies to further enhance patient outcomes.
基金Supported by National Natural Sciences Foundation of China,No.81200649Natural Sciences Foundation of Hubei Province of China,No.2016CFB425Fundamental Research Funds for the Central University,No.2016YXMS236.
文摘Recent studies have confirmed thatβ-adrenergic receptors(β-ARs)are expressed on the surface of osteoblasts and osteoclasts,and that the sympathetic nervous system can regulate bone metabolism by activating them.β-AR blockers(BBs)are commonly used in the treatment of cardiovascular diseases in the elderly.It is important to investigate whether BBs have a beneficial effect on bone metabolism in the treatment of cardiovascular diseases,so as to expand their clinical application.This article reviews the effects of BB on bone metabolism and the progress of clinical research.
文摘Glucagon-like peptide receptor agonists(GLP-1RA)are used to treat type 2 diabetes mellitus and,more recently,have garnered attention for their effect-iveness in promoting weight loss.They have been associated with several gastrointestinal adverse effects,including nausea and vomiting.These side effects are presumed to be due to increased residual gastric contents.Given the potential risk of aspiration and based on limited data,the American Society of Anesthesi-ologists updated the guidelines concerning the preoperative management of patients on GLP-1RA in 2023.They included the duration of mandated cessation of GLP-1RA before sedation and usage of“full stomach”precautions if these medications were not appropriately held before the procedure.This has led to additional challenges,such as extended waiting time,higher costs,and increased risk for patients.In this editorial,we review the current societal guidelines,clinical practice,and future directions regarding the usage of GLP-1RA in patients undergoing an endoscopic procedure.
文摘Metabolic dysfunction-associated steatotic liver disease(MASLD)has become the most common chronic liver disease worldwide,paralleling the rising pandemic of obesity and type 2 diabetes.Due to the growing global health burden and com-plex pathogenesis of MASLD,a multifaceted and innovative therapeutic approach is needed.Incretin receptor agonists,which were initially developed for diabetes management,have emerged as promising candidates for MASLD treatment.This review describes the pathophysiological mechanisms and action sites of three major classes of incretin/glucagon receptor agonists:glucagon-like peptide-1 receptor agonists,glucose-dependent insulinotropic polypeptide receptor agonists,and glucagon receptor agonists.Incretins and glucagon directly or indirectly impact various organs,including the liver,brain,pancreas,gastro-intestinal tract,and adipose tissue.Thus,these agents significantly improve glycemic control and weight management and mitigate MASLD pathogenesis.Importantly,this study provides a summary of clinical trials analyzing the effect-iveness and safety of incretin receptor agonists in MASLD management and provides an in-depth analysis highlighting their beneficial effects on improving liver function,hepatic steatosis,and intrahepatic inflammation.There are emerging challenges associated with the use of these medications in the real world,particularly adverse events,drug-drug interactions,and barriers to access,which are discussed in detail.Additionally,this review highlights the evolving role of incretin receptor agonists in MASLD management and suggests future research directions.
基金Supported by National Natural Science Foundation of China,No.U23A20398 and No.82030007Sichuan Science and Technology Program,No.2022YFS0578.
文摘This editorial takes a deeper look at the insights provided by Soresi and Giannitrapani,which examined the therapeutic potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for metabolic dysfunction-associated fatty liver disease.We provide supplementary insights to their research,highlighting the broader systemic implications of GLP-1RAs,synthesizing the current understanding of their mechanisms and the trajectory of research in this field.GLP-1RAs are revolutionizing the treatment of type 2 diabetes mellitus and beyond.Beyond glycemic control,GLP-1RAs demonstrate cardiovascular and renal protective effects,offering potential in managing diabetic kidney disease alongside renin–angiotensin–aldosterone system inhibitors.Their role in bone metabolism hints at benefits for diabetic osteoporosis,while the neuroprotective properties of GLP-1RAs show promise in Alzheimer's disease treatment by modulating neuronal insulin signaling.Additionally,they improve hormonal and metabolic profiles in polycystic ovary syndrome.This editorial highlights the multifaceted mechanisms of GLP-1RAs,emphasizing the need for ongoing research to fully realize their therapeutic potential across a range of multisystemic diseases.
文摘Background: The objective of this study was to compare and analyze the variations in clinical indices before and after treatment of type 2 mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) that were treated with glucagon-like peptide 1 receptor agonists (GLP-1RAs). Methods: The electronic medical record system was utilized to search for a total of 16 patients with type 2 diabetes complicated by NAFLD who were hospitalized at the First Affiliated Hospital of Yangtze University from October 2022 to April 2023 and treated with GLP-1RA for the first time. The clinical indices were compared before and after 12 weeks of treatment with GLP-1RA. Results: The liver-spleen CT ratio (L/S), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) in all patients treated with GLP-1RA after 12 weeks were significantly different (P 0.05). The patients were categorized into two groups based on the types of GLP-1RAs. The changes in L/S, TC, TG, and LDL-C in the long-acting group after treatment were statistically significant (P Conclusions: GLP-1RAs can improve liver function, regulate lipid metabolism, and reduce the severity of fatty liver in patients with T2DM complicated by NAFLD, which demonstrates the importance of clinical applications.
基金supported by the National Natural Science Foundation of China(No.22077136).
文摘Abscisic acid(ABA),a plant hormone,is crucial for regulating various physiological and developmental processes in plants,including adaptation to biotic and abiotic stresses.Recent advancements have significantly contributed to our understanding of ABA's biosynthetic pathway,transport,signaling pathway,and metabolism.To overcome the limitations of natural ABA,scientists have developed broad-spectrum and highly active agonists of ABA receptors.However,the practical application of these receptor agonists as agrochemicals still faces several challenges.On the other hand,some ABA antagonists have also been developed to differentiate the functional differences among various receptors more accurately.This can help design ABA agonists that can selectively activate specific physiological responses,thereby eliminating the undesired physiological effects induced by ABA.This paper aims to provide a comprehensive overview of the current ABA receptor agonists and antagonists to assist in developing novel ABA functional analogs with improved efficacy and simpler chemical structures that are suitable for agricultural applications.
文摘Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction （MI） and [Ca^2＋]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2＋]i induced by isoproterenol in normal ventricular myocytes （P 〉 0.05）, ICI118, 551 only significantly attenuated the rise of [Ca^2＋]i induced by isoproterenol at four weeks and eight weeks after MI （24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01）. Atenolol had suppressive effects only in the control group and the post-MI group of two weeks （P 〈 0.05）, and propranolol had suppressive effects in the control and all the three post-MI groups （P 〈 0.01）. Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2＋ overload initiated by sympathetic stimulation after MI.
基金the President Support Funding of Xuzhou Medical College,No.09KJZ31the Social Development Program of Xuzhou,No.XM08C063
文摘In the present study,selective β1-adrenergic receptor antagonist CGP20712A and selective β2-adrenergic receptor antagonist ICI 118551 were administered to isolated cardiomyocytes from young （4-6 months）,aged （18-20 months）,and clonidine-pretreated aged （18-20 months） Sprague-Dawley rats.Cardiomyocyte contraction amplitude was measured to assess cardiomyocyte response to the β-adrenergic receptor agonist,isoprenaline.CGP20712A reduced cardiomyocyte contraction amplitude in young and aged groups and significantly reduced contraction amplitude in cells from young rats.ICI 118551 had no effect on cardiomyocyte contraction amplitude in young rats,but significantly decreased contraction amplitude in the aged groups,in particular in the clonidine-pretreated aged rats.Results demonstrated that reduced central sympathetic tone improved cardiomyocyte contraction in aged rats by improving the response of β2-adrenergic receptor to isoprenaline.
