链脲霉素实验性大鼠妊娠糖尿病对子鼠心肌细胞超微结构的影响

目的:通过研究链脲霉素(streptoaotocin,STZ)实验性大鼠妊娠糖尿病对子鼠在不同孕期心肌细胞超微结构的影响,探讨妊娠糖尿病致胎儿心脏发育异常的发生机制.方法:将54只SD孕鼠分为STZ注射组(30只)和柠檬酸缓冲液注射组(24只)作对照观察,按取材时孕龄不同将两组又分为第13、16和19天3个亚组.对STZ注射组孕鼠,给予新配质量分数为2%STZ溶液,按STZ 40mg/kg,一次性腹腔注射,3 d后空腹尾静脉采血监测血糖,并测尿糖、体质量.对照组用同样方法注射等量的柠檬酸钠缓冲液.孕鼠于孕龄第13、16、19天随机分批剖宫,取子鼠心脏组织做超微结构观察.结果:STZ注射组子鼠心肌细胞超微结构可见不同程度病理变化:细胞间连接较少、间隙宽窄不一,肌束排列不规整,胞膜结构不完整;胞质电子密度较高,线粒体肿胀呈空泡状气球样变,嵴减少,粗面内质网减少、扩张,可见脂质样小滴;胞核大小不一,不规则圆形,核膜结构不清,核染色质分布不均,可见异染色质;胞外基质可见有胶原纤维排列成束状,毛细血管腔外可见红细胞,有细胞器崩解痕迹.结论:STZ实验性大鼠妊娠糖尿病可致子鼠心肌发生超微结构的异常改变,可能为糖尿病母亲致儿心脏畸形的病理基础.

The ultrastructural effects of the heart cells of the fetus of rats with streptozotocin-induced gestational diabetes mellitus rats

Aim:To explore the mechanism of abnormal ultrastructural change of the heart tissues in fetus of diabetic mother(IDM),the ultrastructural changes of heart tissues in infant of streptozotocin-induced diabetic pregnant rats are studied. Methods:The SD pregnant rats were divided into two groups randomly.One was GDM group(n=27).All rats were injected STZ or PBS respectively at abdominal cavity.Blood glucose,urine glucose and body weight every day were observed,after 72 h when rats were given STZ or PBS,all rats were uterine-incision delived to obtain the materials from embryo heart tissues at gestation 13th,16th,19th day randomly to observe the ultrastructure of the heart tissues.Results:In the embryo rats' heart of DM group,the pathological change of cardiocyte ultrastructure at different extent could be seen:the cell-cell junction is less,the width is different,the muscle bundle arranges irregularly,and the cell membrane was not integrate.The electron density of cytoplasm was higher,the mito chondria became swelling even balloon degeneration,the crista was less,the rough endoplasmic reticulum(RER) became decrease and dilate,there was some small fatty substance.The size and shape of nucleus was different,like irregular spherical,nuclear membrane structure was ambiguity,the disposition of chromatin was uneven,and there was some abnormal chromatin.The collagen fiber of extracellular substratum arraies fasc,there was akaryocyte in the outer of capillary lumen and some chip organelle.Conclusion:Streptozotocin-induced gestational diabetes mellitus may cause abnormal change of ultrastructure in the heart tissues,which may be pathological foundation of cardiac anomalies of IDM.