McGrath G M, McNeill J H
Can J Cardiol. 1986 May-Jun;2(3):164-9.
The effect of insulin treatment on myocardial ultrastructure was studied in experimentally induced diabetic male rats. Rats received an intravenous injection of 60 mg/kg streptozotocin and were tested for glycosuria 3 days later. Half of these animals were then given 3.0 U of protamine zinc insulin daily subcutaneously and again tested for glycosuria. The significant loss in weight observed in the untreated diabetics was prevented in the insulin-treated diabetics. Electron microscopic observation of the left ventricular myocardium from 3 month untreated diabetics revealed mild edema adjacent to the sarcoplasmic reticulum. A more severe form of edema, focal in nature, was also observed. Some distended mitochondria and disrupted banding were associated with these focal areas of edema. Increased lipid levels and intramitochondrial dense staining particles were found in the untreated diabetics. On the other hand, hearts from insulin-treated diabetics did not exhibit these alterations. They did, however, exhibit mitochondrial clumping which was also seen in the untreated diabetics and the same capillary changes. The latter involved a thickening of the lamina densa, loss of the lamina lucida and an increased number of micropinocytotic vesicles in the capillary walls. These results suggest that insulin treatment is capable of preventing only some of the ultrastructural changes induced by streptozotocin-diabetes in rat hearts.
在实验诱导的糖尿病雄性大鼠中研究了胰岛素治疗对心肌超微结构的影响。大鼠静脉注射60mg/kg链脲佐菌素，3天后检测尿糖。然后，这些动物中有一半每天皮下注射3.0U精蛋白锌胰岛素，并再次检测尿糖。胰岛素治疗的糖尿病大鼠防止了未治疗糖尿病大鼠中观察到的显著体重减轻。对3个月未治疗的糖尿病大鼠左心室心肌的电子显微镜观察显示，肌浆网附近有轻度水肿。还观察到一种更严重的、局灶性的水肿形式。一些肿胀的线粒体和破坏的条纹与这些局灶性水肿区域有关。在未治疗的糖尿病大鼠中发现脂质水平升高和线粒体内致密染色颗粒。另一方面，胰岛素治疗的糖尿病大鼠的心脏没有表现出这些改变。然而，它们确实表现出线粒体聚集，这在未治疗的糖尿病大鼠中也可见，并且有相同的毛细血管变化。后者包括致密层增厚、透明层丧失以及毛细血管壁中微吞饮小泡数量增加。这些结果表明，胰岛素治疗仅能预防链脲佐菌素诱导的糖尿病大鼠心脏中的一些超微结构变化。
