Morris G S, Baldwin K M, Lash J M, Hamlin R L, Sherman W M
Department of Physiology and Biophysics, University of California, Irvine 92717.
J Appl Physiol (1985). 1990 Jul;69(1):380-3. doi: 10.1152/jappl.1990.69.1.380.
Recent evidence suggests that exercise training may significantly increase the expression of the cardiac myosin isozyme V1 in the diabetic heart, a change associated with improved cardiac functional capacity. To test this hypothesis, cardiac myofibrillar adenosinetriphosphatase (ATPase) activity and myosin isozyme profiles were determined in trained and sedentary male hyperinsulinemic obese Zucker (OZT, OZS) and obese Wistar (OWT, OWS) rats. Lean sedentary (LZS, LWS) animals served as age-matched controls. Myofibrillar ATPase activity and the relative quantity of the high-ATPase isozyme V1 was significantly lower in both strains of sedentary obese rats than in the respective lean sedentary controls (P less than 0.05). Both 5 (OZT) and 10 wk (OWT) of moderate treadmill training increased these markers of cardiac myosin biochemistry in the obese animals (P less than 0.05). Thus, endurance exercise training remodels the cardiac isomyosin profile of hyperinsulinemic rats and, in doing so, may enhance cardiac contractility and functional capacity. Such changes may reflect an improvement in glucose availability and utilization in these hearts.
最近的证据表明，运动训练可能会显著增加糖尿病心脏中心肌肌球蛋白同工酶V1的表达，这种变化与心脏功能能力的改善有关。为了验证这一假设，我们测定了经过训练和久坐不动的雄性高胰岛素血症肥胖 Zucker 大鼠（OZT、OZS）和肥胖 Wistar 大鼠（OWT、OWS）的心肌肌原纤维腺苷三磷酸酶（ATPase）活性和肌球蛋白同工酶谱。瘦的久坐不动的（LZS、LWS）动物作为年龄匹配的对照。久坐不动的肥胖大鼠的两个品系中，肌原纤维ATPase活性和高ATPase同工酶V1的相对量均显著低于各自瘦的久坐不动的对照（P<0.05）。5周（OZT）和10周（OWT）的中等强度跑步机训练均增加了肥胖动物心肌肌球蛋白生物化学的这些指标（P<0.05）。因此，耐力运动训练重塑了高胰岛素血症大鼠的心脏异肌球蛋白谱，这样做可能会增强心脏收缩力和功能能力。这些变化可能反映了这些心脏中葡萄糖可用性和利用率的改善。
