The study of exercise treatment for cardiovascular diseases

本文观察了慢性运动(ET)对自发性高血压大鼠(SHR)胸主动脉去甲肾上腺素敏感性和脂肪细胞脂解的影响。ET后，SHR大鼠和正常血压大鼠的主动脉对去甲肾上腺素的敏感性均减弱。ET后主动脉对去甲肾上腺素的敏感性在内皮剥离的主动脉中仍然很明显，但程度比内皮完整的主动脉要小。有内皮和无内皮时，60 mM Kc1诱导的张力在对照组和训练后的SHR大鼠之间无显著差异。结果提示，SHR和正常血压大鼠在ET后，内皮依赖性释放因子的水平可能与去甲肾上腺素的反应有关。在单独的实验中，研究了ET后SHR大鼠的脂肪细胞脂解作用。与正常血压大鼠相比，未训练的SHR大鼠被不同激动剂如异丙肾上腺素、多巴酚丁胺、沙丁胺醇、BRL37344和二丁酰环磷酸腺苷所刺激的脂肪细胞脂解作用减弱。然而，ET显著增加了每种激动剂刺激的脂肪细胞脂肪分解，尽管SHR大鼠的最大反应比正常血压运动训练的大鼠要小。因此，ET显著改变SHR大鼠主动脉对去甲肾上腺素的反应和脂肪细胞脂解反应对各种激动剂的反应。

The effects of chronic physical exercise (ET) on the sensitivity of thoracic aorta to norepinephrine and on adipocyte lipolysis were investigated in spontaneously hypertensive rats (SHR). After ET, the attenuated sensitivity of aorta to norepinephrine was observed in SHR rats as well as in normotensive rats. This attenuated sensitivity of aorta to norepinephrine after ET was still evident in endothelium-denuded aorta, but to a lesser extent than in endothelium-intact aorta. No significant difference in 60 mM KC1-induced tension between control and trained SHR rats was observed with or without endothelium after ET.The results suggest that levels of endothelium-dependent releasing factor may increase in response to norepinephrine after ET in SHR rats as well as in normotensive rats. In the separate experiments, adipocyte lipolysis was investigated in SHR rats after ET.Adipocyte lipolysis stimulated by various agonists, such as isoproterenol, dobutamine, salbutamol, BRL37344 and dibutyryl cyclic AMP, was blunted in non-trained SHR rats compared with normotensive rats. However, ET significantly increased adipocyte lipolysis stimulated by each agonist, although the maximal responses were less in SHR rats than in normotensive exercise-trained rats. Thus, ET significantly alter the responses of aorta to norepinephrine and those of adipocyte lipolysis to various agonists in SHR rats.