摘要
目的动态观察新生大鼠坏死性小肠结肠炎(NEC)发病过程中肠细胞凋亡率变化及其与肠损伤关系。方法40只新生SD大鼠随机分成对照组(C)和模型组(M)。对照组8只;模型组32只,在出生48h开始给予鼠配方奶人工喂养,100%氮气缺氧90s,4℃冷刺激10min,每天2次,连续3d,建立新生大鼠NEC模型;模型组开始造模后24h(M24)、48h(M48)、72h(造模结束,M72)及造模结束后24h(M96)分别处死8只,留取肠管进行肠组织损伤评分和肠细胞凋亡率检测(流式细胞仪)。组织学评分≥2确定为NEC。各组随机选取1份回盲部近端小肠标本进行肠黏膜透射电镜检查。采用SPSS11.0统计学软件进行统计分析,α=0.05为显著性检验标准。结果透射电镜显示模型组大鼠肠黏膜出现大量凋亡细胞,形成凋亡小体。对照组、M24、M48、M72和M96肠组织损伤评分分别为(0.08±0.15)、(1.38±0.42)、(1.46±0.69)、(1.58±0.30)分和(3.33±0.59)分,肠细胞凋亡率分别为4.8%±2.9%、12.8%±6.3%、14.9%±5.5%、17.7%±5.5%和27.6%±9.9%。肠损伤程度与肠细胞凋亡率呈显著正相关(r凋亡率=0.853,P<0.01)。结论新生鼠肠细胞凋亡增加是NEC肠组织损伤起始事件;随时间延长,肠细胞凋亡增加程度进一步加重;肠细胞凋亡增加是造成新生鼠NEC肠道进行性损伤的病理基础。
Objective To observe the change of intestinal cells apoptosis severity in neonatal rate NEC progression, and analyze its correlation with intestinal injury. Methods Fourty neonatal Sprague-Dawley rats （48 hours olds, weight： 5 - 10 g） were randomly divided into the model group （n = 32） and the control group （n = 8）. Rats in the model group were fed with rat milk substitute after 48hours of life, and various stimulation （ suffocated with 100% nitrogen gas for 90s, exposed under 4 ℃ condition for 10 minutes, two times a day） for longest duration of 3 days. Rats in the model group further subdivided evenly into four groups, and executed at 24 hours （ M24, n = 8）, 48 hours （ M48, n = 8）, 72 hours （M72, n = 8） after stimulation started, and 96 hours later （24 hours after the last stimulation, M96 , n =8 ）. At the end of the experiment, the rats in the control group were also executed. Intestines of both groups were collected for electron microscopic observation and estimated the apoptosis rate of intestinal cells （flow cytometer）. Histological score ≥2 were diagnosed as NEC. The ileocecum proximal intestine of one rat from each group was obtained for pathological examination and evaluating the score of intestinal injury. SPSS 11.0 software for Windows was used in all statistical tests, α = 0.05 was considered significant. Results Transmission electron microscopy showed a large number of apoptotic cells in the model group＇s intestinal mucosa, and formatted apoptotic bodies. The score of intestinal injury in the control group, M24, M48, M72, M96 group were 0. 08 ±0. 15, 1.38 ±0.42, 1.46 ±0. 69, 1.58 ± 0.30, 3.33 ± 0. 59 and the apoptosis rate of intestinal cells were 4. 8% ± 2.9%, 12. 8%± 6.3%, 14.9% ± 5.5%, 17.7% ± 5.5%, 27.6% ±9.9%, respectively. The intestinal injury severity was significantly correlated with the cell apoptosis ratio positively （ r = 0. 853, P 〈 0. 01 ）. Conclusion The increase of neonatal rate intestinal cells apoptosis ratio is the initial event of NEC intestinal tissue injury; as time progress, intestinal cell apoptosis would increase; the incensement of intestinal cell apoptosis is the fundamental pathophysiology in intestinal progressive injury.
出处
《中国新生儿科杂志》
CAS
2008年第6期349-352,389,共5页
Chinese Journal of Neonatology
基金
福建省卫生厅青年科研课题资助(2007-1-10)
