LaPier T L, Swislocki A L, Clark R J, Rodnick K J
Department of Physical and Occupational Therapy, Idaho State University, Pocatello 83209, USA.
Am J Hypertens. 2001 Jul;14(7 Pt 1):708-15. doi: 10.1016/s0895-7061(01)01285-7.
We evaluated the effects of voluntary exercise training on glucose metabolism and measures of insulin sensitivity in female spontaneously hypertensive rats (SHR). Age-matched Wistar-Kyoto rats (WKY) were used as normotensive controls. Exercising SHR were housed in running wheels for 8 weeks (SHRx8) or 16 weeks (SHRx16). At 22 weeks of age, we measured systolic blood pressure, performed oral glucose tolerance tests, and determined hexokinase activity and glucose transporter (GLUT) 4 content in skeletal muscle to assess intracellular glucose metabolism. Blood pressure was lower in WKY (139+/-12 mm Hg) than untrained SHR (216+/-13 mm Hg). Exercise training caused a reduction in blood pressure (-18 mm Hg) for SHRx8. After a brief (5-h) fast, serum glucose was lower in SHR that exercised compared with sedentary SHR, whereas insulin concentrations were identical between all SHR and WKY. Corresponding free fatty acids (FFA) were twofold higher in SHR than in WKY. In response to glucose, SHR demonstrated higher glucose and FFA responses, with exercise decreasing the glucose values in a dose-dependent manner. Although the insulin response was comparable in all groups, the glucose-to-insulin ratio was higher in SHR, indicating a relative insulin resistance for both glucose disposal and suppression of free fatty acids. Hexokinase activity and GLUT4 content were elevated 1.4- and 2.8-fold, respectively, in plantaris muscle of SHRx16, suggesting an improvement in the capacity for glucose transport and phosphorylation with exercise. These results provide evidence that voluntary running in female SHR lowers blood pressure and selectively increases glucose uptake and insulin action, but not suppression of FFA.
我们评估了自愿运动训练对雌性自发性高血压大鼠（SHR）葡萄糖代谢及胰岛素敏感性指标的影响。将年龄匹配的Wistar-Kyoto大鼠（WKY）作为正常血压对照。让运动的SHR置于跑轮中8周（SHRx8）或16周（SHRx16）。在22周龄时，我们测量了收缩压，进行了口服葡萄糖耐量试验，并测定了骨骼肌中的己糖激酶活性和葡萄糖转运蛋白（GLUT）4含量，以评估细胞内葡萄糖代谢。WKY的血压（139±12毫米汞柱）低于未训练的SHR（216±13毫米汞柱）。运动训练使SHRx8的血压降低了（-18毫米汞柱）。短暂禁食（5小时）后，运动的SHR血清葡萄糖低于久坐的SHR，而所有SHR和WKY之间的胰岛素浓度相同。相应的游离脂肪酸（FFA）在SHR中比在WKY中高出两倍。对葡萄糖的反应中，SHR表现出更高的葡萄糖和FFA反应，运动以剂量依赖的方式降低葡萄糖值。尽管所有组的胰岛素反应相当，但SHR中的葡萄糖与胰岛素比值更高，表明在葡萄糖处理和游离脂肪酸抑制方面存在相对胰岛素抵抗。SHRx16的跖肌中己糖激酶活性和GLUT4含量分别升高了1.4倍和2.8倍，表明运动可改善葡萄糖转运和磷酸化能力。这些结果提供了证据，表明雌性SHR自愿跑步可降低血压，并选择性地增加葡萄糖摄取和胰岛素作用，但不能抑制FFA。
