Division of Cardiology, Duke University Medical Center, Durham, North Carolina, USA.
Microcirculation. 2012 Nov;19(8):729-38. doi: 10.1111/j.1549-8719.2012.00210.x.
Exercise (RUN) prevents declines in insulin-mediated vasodilation, an important component of insulin-mediated glucose disposal, in rats prone to obesity and insulin resistance.
Determine whether RUN (1) improves insulin-stimulated vasodilation after insulin resistance has been established, and (2) differentially affects arterioles from red and white muscle.
Insulin signaling and vasoreactivity to insulin (1-1000 μIU/mL) were assessed in 2A from the Gw and Gr of SED OLETF rats at 12 and 20 weeks of age (SED12, SED20) and those undergoing RUN (RUN20) or caloric restriction (CR20; to match body weight of RUN) from 12 to 20 weeks.
Glucose and insulin responses to i.p. glucose were reduced in RUN20, elevated in SED20 (p < 0.05 vs. SED12), and maintained in CR20. Insulin-stimulated vasodilation was greater in Gw but not Gr, 2As of RUN20 (p < 0.01 vs. all groups), and was improved by ET-1 receptor inhibition in Gw 2As from SED20 and CR20 (p < 0.05). There were no differences in microvascular insulin signaling among groups or muscle beds.
RUN selectively improved insulin-mediated vasodilation in Gw 2As, in part through attenuated ET-1 sensitivity/production, an adaptation that was independent of changes in adiposity and may contribute to enhanced insulin-stimulated glucose disposal.
运动（RUN）可防止易肥胖和胰岛素抵抗的大鼠中胰岛素介导的血管舒张功能下降，这是胰岛素介导的葡萄糖处置的重要组成部分。
确定 RUN 是否（1）改善胰岛素抵抗确立后胰岛素刺激的血管舒张，和（2）对红色和白色肌肉的小动脉产生不同影响。
在 12 周和 20 周龄（SED12、SED20）SED 肥胖型 OLETF 大鼠的 Gw 和 Gr 2A 中评估胰岛素信号和对胰岛素（1-1000μIU/ml）的血管反应性，以及从 12 周至 20 周进行 RUN（RUN20）或热量限制（CR20；以匹配 RUN 的体重）的大鼠。
RUN20 组的腹腔内葡萄糖和胰岛素反应降低，SED20 组升高（与 SED12 相比，p<0.05），CR20 组维持不变。 Gw 但不是 Gr 的 2A 中，RUN20 的胰岛素刺激血管舒张更大（与所有组相比，p<0.01），且 SED20 和 CR20 的 Gw 2A 中通过 ET-1 受体抑制可改善（p<0.05）。各组或肌肉床之间的微血管胰岛素信号没有差异。
RUN 选择性改善 Gw 2A 中的胰岛素介导的血管舒张，部分通过减轻 ET-1 敏感性/产生，这种适应与肥胖变化无关，可能有助于增强胰岛素刺激的葡萄糖处置。
