Aim To explore the reason that the antiarrhythmic effect of the extract oftraditional Chinese medicinal herb, matrine, is weaker than quinidine and verapamil by comparison ofthe effect and efficacy of matrine on vario...Aim To explore the reason that the antiarrhythmic effect of the extract oftraditional Chinese medicinal herb, matrine, is weaker than quinidine and verapamil by comparison ofthe effect and efficacy of matrine on various kinds of transmembrane ionic currents with those ofquinidine and verapamil; and to demonstrate the best targets for antiarrhythmic drugs. MethodsWhole-cell patch-clamp techniques were used to record the action potential and ionic currents insingle cells of rat ventricular myocytes. Aconitine was used to induce the changes of ioniccurrents, then study the effects of matrine and quinidine, verapamil on aconitine-induced unbalancedchannel currents and action potential. Results Aconitine 1 μmol·L^(-1) induced significantchanges in transmembrane currents and action potential in single cells of rat ventricular myocytes.APD was significantly prolonged by aconitine. Simultaneously, aconitine increased sodium, L-typecalcium and inward rectifier potassium currents. Matrine 100 μmol· L^(-1) reversed theaconitine-induced changes of sodium current (I_(Na)) from (-70.2+- 10.5) pA/pF to ( - 39.6+-4.0)pA/pF(n = 5, P < 0.05 vs aconitine); L-type calcium current (I_(Ca-L)) from (20.4+- 3.8) pA/pF to (- 12.9+- 2.9) pA/pF ( n = 6, P < 0.01); the inward rectifier potassium current (I_(k1) ) from (-32.2+- 1.08) pA/pF to ( -24.0+-3.4) pA/pF (n = 6, P < 0.01), and action potential duration. Thereversal effects of quinidine and verapamil on aconitine-induced changes of APD and ionic currentswere more marked than matrine. Conclusion Aco-nitine significantly disturbs the normal equilibriumof ion channels in ventricular myocytes. It induces changes of I_(Na), I_(Ca-L), I_(K1) andprolongation of action potential duration. Matrine at concentration 50 or 100 μmol·L^(-1)statistically significantly suppresses aconitine-induced changes of APD and ionic currents. Thepotency and efficacy of inhibitory effect of matrine are markedly weaker than those of commonly usedverapamil and quinidine.展开更多
Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and se...Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and seedling incubation for cultivation is limited, especially the early development. In this study, tetrasporohyte and gametophyte of P. urceolata were taken as the study materials in Huiquan Bay, Qingdao, China. The cleaned and sterilized tetrasporophytes and gametophytes were pre-cultured in sterilized seawater, then nurtured at 18℃, 25 μmol photons m^-2 s^-1 in 12：12 h （light：dark） photoperiod. Continuous observation under microscope showed that the early development consists of bipolar division stage and seedling stage. In the division stage, tetraspores germinate into bipolar sporelings that further differentiate into a colorless rhizoidal portion and a lightly pigmented upright shoot. The lightly pigmented rhizoidal cell develops to a rhizoid and the larger pigmented cell transforms to an erect axis. In the seedling stage, several quasi-protuberances appear on the erect axis and form juvenile seedlings. The results demonstrate the culture of P. urceolata from tetraspores under laboratory conditions.展开更多
The Luo Rudy models of mammalian ventricular cell were chosen in studying cardiac electrophysiology. Rush and Larsen’s algorithm and adaptive time step methods were used to solve the ordinary differential equations (...The Luo Rudy models of mammalian ventricular cell were chosen in studying cardiac electrophysiology. Rush and Larsen’s algorithm and adaptive time step methods were used to solve the ordinary differential equations (ODE’s). The operator splitting (or time splitting) and adaptive time step methods were used to solve the partial differential equations (PDE’s) in cardiac tissue conduction models. The alternating direction implicit (ADI) method was used to integrate the PDE. Using these methods we accomplished the simulation programs of single cardiomyocyte model, one dimensional cable model(1 D) and two dimensional(2 D) tissue model. The methods of initiating spiral waves were studied with these software. The data getting from 2 D simulation can be used for further study on isopotential contour lines, spiral wave tip trajectories, and pseudo ECG. The software for computer simulation have been successfully used in simulation studying of electrophysiology properties of single cardiomyocyte, conduction in one dimensional cable model(1 D) and two dimensional(2 D) tissue model.展开更多
文摘Aim To explore the reason that the antiarrhythmic effect of the extract oftraditional Chinese medicinal herb, matrine, is weaker than quinidine and verapamil by comparison ofthe effect and efficacy of matrine on various kinds of transmembrane ionic currents with those ofquinidine and verapamil; and to demonstrate the best targets for antiarrhythmic drugs. MethodsWhole-cell patch-clamp techniques were used to record the action potential and ionic currents insingle cells of rat ventricular myocytes. Aconitine was used to induce the changes of ioniccurrents, then study the effects of matrine and quinidine, verapamil on aconitine-induced unbalancedchannel currents and action potential. Results Aconitine 1 μmol·L^(-1) induced significantchanges in transmembrane currents and action potential in single cells of rat ventricular myocytes.APD was significantly prolonged by aconitine. Simultaneously, aconitine increased sodium, L-typecalcium and inward rectifier potassium currents. Matrine 100 μmol· L^(-1) reversed theaconitine-induced changes of sodium current (I_(Na)) from (-70.2+- 10.5) pA/pF to ( - 39.6+-4.0)pA/pF(n = 5, P < 0.05 vs aconitine); L-type calcium current (I_(Ca-L)) from (20.4+- 3.8) pA/pF to (- 12.9+- 2.9) pA/pF ( n = 6, P < 0.01); the inward rectifier potassium current (I_(k1) ) from (-32.2+- 1.08) pA/pF to ( -24.0+-3.4) pA/pF (n = 6, P < 0.01), and action potential duration. Thereversal effects of quinidine and verapamil on aconitine-induced changes of APD and ionic currentswere more marked than matrine. Conclusion Aco-nitine significantly disturbs the normal equilibriumof ion channels in ventricular myocytes. It induces changes of I_(Na), I_(Ca-L), I_(K1) andprolongation of action potential duration. Matrine at concentration 50 or 100 μmol·L^(-1)statistically significantly suppresses aconitine-induced changes of APD and ionic currents. Thepotency and efficacy of inhibitory effect of matrine are markedly weaker than those of commonly usedverapamil and quinidine.
基金Supported by National Key Technology Support Program, Development Program of China (No.2006AA09Z21)National Natural Science Foundation of China (No. 40618001 and N_CUHK438/06)Shandong Agricultural Seed Stock Breeding Project
文摘Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and seedling incubation for cultivation is limited, especially the early development. In this study, tetrasporohyte and gametophyte of P. urceolata were taken as the study materials in Huiquan Bay, Qingdao, China. The cleaned and sterilized tetrasporophytes and gametophytes were pre-cultured in sterilized seawater, then nurtured at 18℃, 25 μmol photons m^-2 s^-1 in 12：12 h （light：dark） photoperiod. Continuous observation under microscope showed that the early development consists of bipolar division stage and seedling stage. In the division stage, tetraspores germinate into bipolar sporelings that further differentiate into a colorless rhizoidal portion and a lightly pigmented upright shoot. The lightly pigmented rhizoidal cell develops to a rhizoid and the larger pigmented cell transforms to an erect axis. In the seedling stage, several quasi-protuberances appear on the erect axis and form juvenile seedlings. The results demonstrate the culture of P. urceolata from tetraspores under laboratory conditions.
基金Project Supported by National Natural Science Foundation of China(No.3 0 10 0 0 67)
文摘The Luo Rudy models of mammalian ventricular cell were chosen in studying cardiac electrophysiology. Rush and Larsen’s algorithm and adaptive time step methods were used to solve the ordinary differential equations (ODE’s). The operator splitting (or time splitting) and adaptive time step methods were used to solve the partial differential equations (PDE’s) in cardiac tissue conduction models. The alternating direction implicit (ADI) method was used to integrate the PDE. Using these methods we accomplished the simulation programs of single cardiomyocyte model, one dimensional cable model(1 D) and two dimensional(2 D) tissue model. The methods of initiating spiral waves were studied with these software. The data getting from 2 D simulation can be used for further study on isopotential contour lines, spiral wave tip trajectories, and pseudo ECG. The software for computer simulation have been successfully used in simulation studying of electrophysiology properties of single cardiomyocyte, conduction in one dimensional cable model(1 D) and two dimensional(2 D) tissue model.
