Fein F S, Kornstein L B, Strobeck J E, Capasso J M, Sonnenblick E H
Circ Res. 1980 Dec;47(6):922-33. doi: 10.1161/01.res.47.6.922.
Diabetes mellitus is associated frequently with congestive heart failure in humans, even in the absence of associated coronary disease or hypertension. Nevertheless, the effects of the diabetic state on myocardial mechanics have not been studied. Accordingly, diabetes was induced in female Wistar rats by injection of streptozotocin (60 mg/kg). Left ventricular papillary muscles were studied 5, 10, and 30 weeks later and compared with controls. Relaxation was delayed significantly and velocity of shortening was depressed at all loads. However, the passive and active force-length curves, as well as the series elastic properties, were not altered. The changes in cardiac performance were found over a range of muscle lengths, stimulus frequencies, and bath concentrations of calcium, glucose, and norepinephrine. The duration of diabetes had no major effect on the mechanical changes observed. The possible influences of drug-induced cardiac toxicity, malnutrition, and altered thyroid hormone levels have been considered; the latter two factors could not be excluded completely from having some influence on the mechanical properties of diabetic cardiac muscle. Evidence is cited showing abnormalities in calcium uptake by sarcoplasmic reticulum and depressed actomyosin ATPase activity. Thus a cardiomyopathic state has been produced in the rat consequent to the induction of experimental diabetes mellitus. Various mechanisms for this entity have been suggested.
糖尿病在人类中常常与充血性心力衰竭相关，即使在没有相关冠状动脉疾病或高血压的情况下也是如此。然而，糖尿病状态对心肌力学的影响尚未得到研究。因此，通过注射链脲佐菌素（60mg/kg）在雌性Wistar大鼠中诱导糖尿病。在5、10和30周后研究左心室乳头肌，并与对照组进行比较。在所有负荷下，松弛明显延迟，缩短速度降低。然而，被动和主动力-长度曲线以及串联弹性特性并未改变。在一系列肌肉长度、刺激频率以及钙、葡萄糖和去甲肾上腺素的浴液浓度范围内发现了心脏功能的变化。糖尿病的持续时间对观察到的力学变化没有重大影响。已经考虑了药物诱导的心脏毒性、营养不良和甲状腺激素水平改变的可能影响；后两个因素对糖尿病心肌力学特性的影响不能完全排除。引用的证据表明肌浆网钙摄取异常和肌动球蛋白ATP酶活性降低。因此，实验性糖尿病诱导后在大鼠中产生了一种心肌病状态。已经提出了关于这个实体的各种机制。
