王蕴红+张雪琳+赵明华

摘 要：研究不同训练状态大鼠心肌糖皮质激素受体（GR）和盐皮质激素受体（MR）的表达规律，探讨其在运动心肌适应过程中可能产生的作用。方法：大鼠分别采用一次耐力运动、4周和10周的递增负荷耐力运动训练方案，并在末次运动后0 h、3 h、24 h 取材，采用Western blot 方法测定左室心肌相应的指标。结果：肾上腺重量以及肾上腺/体重在4周和10周的训练大鼠均显著增加；而心肌GR和MR的表达在4周递增负荷耐力训练后与安静对照组比较显著下降，经过10周递增负荷耐力训练后，受体表达量与安静对照组无明显差异。一次、4周和10周的耐力运动对大鼠心肌p-SGK1/SGK1没有明显影响；但心肌HSP70的表达量随着运动训练的持续，呈递增性提高。结论：大鼠心肌GR和MR表达以及受体与配体的亲和力与运动训练状态有关，这些变化可能参与了运动心肌的适应过程。

关键词：运动；心肌；糖皮质激素受体；盐皮质激素受体；血清和糖皮质激素调节激酶1

中图分类号：G 804.2 文章编号：1009-783X（2017）04-0375-04 文献标识码：A

Abstract：Objective：To characterize the expression pattern of glucocorticoid receptor （GR） and mineralocorticoid receptor （MR） of different exercise training status in hearts so as to investigate their roles in exercise -induced cardiac adaptation. Methods： Rats were subjected to either a single bout of exercise， 4-week or 10-week exercise training respectively and then euthnized at 0h， 3h and 24h after last run. Protein level of left ventricle was measured by Western blotting. Results： Adrenal weight to body weight ratio was significantly increased in 4-week and 10-week trained rats. After 4-week training， the basal expressions of GR and MR were significantly decreased， but no change was observed in GR and MR expression after 10-week of training. No change was observed in p-SGK1 to SGK1 ratio in all exercised groups， while a significant increase in the expression of HSP70 both in response to acute exercise and at the basal level in the exercise trained rats. Conclusion： The expression pattern of GR and MR， and the affinity of glucocorticoid receptor might influence with training status and these adaptive changes might be involved in exercise-induced cardiac adaptation.

Keywords： exercise； cardiac muscle； GR； MR； SGK1

糖皮质激素是主要的应激激素，它对心肌细胞的作用不仅由GR（glucocorticoid receptor）介导，还可由MR（mineralocorticoid receptor）介导[1-3]。研究发现，GR在心脏的正常发育和功能中起关键的作用[3-4]，而MR则在心血管疾病的发生和发展中发挥重要的作用[3，5-6]。另有研究显示，高水平运动员安静时糖皮质激素水平轻微升高，而下丘脑—垂体—肾上腺对急性运动的反应性下降[7]。这些结果提示，循环中糖皮質激素水平与运动诱发的心肌适应可能有关。有报道显示，长期循环中糖皮质激素升高是心脏病独立的致病因素[4]，糖皮质激素能够诱发心肌肥大[8-9]；……