Heyliger C E, Prakash A, McNeill J H
Am J Physiol. 1987 Mar;252(3 Pt 2):H540-4. doi: 10.1152/ajpheart.1987.252.3.H540.
Diabetes mellitus is frequently associated with a primary cardiomyopathy. The mechanisms responsible for this heart disease are not clear, but an alteration in myocardial Ca2+ transport is believed to be involved in its development. Even though sarcolemma plays a crucial role in cellular Ca2+ transport, little appears to be known about its Ca2+ transporting capability in the diabetic myocardium. In this regard, we have examined the status of the cardiac sarcolemmal Ca2+ pump during diabetes mellitus. Purified sarcolemmal membranes were isolated from male Wistar diabetic rat hearts 8 wk after streptozotocin injection (55 mg/kg iv). Ca2+ pump activity assessed by measuring its Ca2+-stimulated adenosine triphosphatase and Ca2+-uptake ability in the absence and presence of calmodulin was significantly depressed in the diabetic myocardium relative to controls. These results did not appear to have been influenced by the minimal sarcoplasmic reticular and mitochondrial contamination of this membrane preparation. Hence, it appears that the sarcolemmal Ca2+ pump is defective in the diabetic myocardium and may be involved in the altered Ca2+ transport of the heart during diabetes mellitus.
糖尿病常与原发性心肌病相关。导致这种心脏病的机制尚不清楚，但心肌钙转运的改变被认为参与了其发展。尽管肌膜在细胞钙转运中起关键作用，但关于其在糖尿病心肌中的钙转运能力似乎知之甚少。在这方面，我们研究了糖尿病期间心脏肌膜钙泵的状态。从链脲佐菌素注射（55mg/kg静脉注射）8周后的雄性Wistar糖尿病大鼠心脏中分离纯化的肌膜。通过测量其钙刺激的三磷酸腺苷酶以及在有无钙调蛋白情况下的钙摄取能力来评估的钙泵活性，在糖尿病心肌中相对于对照组显著降低。这些结果似乎并未受到该膜制剂中最小程度的肌浆网和线粒体污染的影响。因此，看来糖尿病心肌中的肌膜钙泵存在缺陷，并且可能参与了糖尿病期间心脏钙转运的改变。
