Rupp H, Wahl R
Institute of Physiology II, University of Tübingen, Federal Republic of Germany.
J Appl Physiol (1985). 1990 Mar;68(3):973-8. doi: 10.1152/jappl.1990.68.3.973.
To define the physiological signals involved in the redirection of myosin expression in the swim-exercised rat, the relative influence of thyroid hormones and beta-adrenergic blockade was determined. Swimming exercise resulted in an increased proportion of myosin V1 (60.9 +/- 9.7 vs. 38.0 +/- 4.1% of sedentary rats fed ad libitum) but did not increase serum concentrations of total and free thyroxine or triiodothyronine determined either 17-21 h or immediately after swimming. The proportion of V1 increased, although intermittently food-deprived rats with the body weight of swimming rats exhibited a reduced proportion of V1 (23.5 +/- 2.7). When swimming rats had only intermittent access to food, they had reduced concentrations of all thyroid hormones, but the proportion of V1 (51.5 +/- 7.6) was nonetheless increased. Thus the redirection of myosin expression cannot be attributed to an increased secretion of thyroid hormones. The influence of the adrenergic system was assessed by treating swimming rats with the beta-blocking drug atenolol. Because the proportion of V1 was reduced, but thyroid hormones were not affected, beta-adrenergic blockade seems to influence myosin expression independently of thyroid hormones.
为了确定参与游泳训练大鼠肌球蛋白表达重定向的生理信号，我们测定了甲状腺激素和β-肾上腺素能阻滞剂的相对影响。游泳训练导致肌球蛋白V1的比例增加（自由进食的久坐大鼠中肌球蛋白V1占比为38.0±4.1%，而游泳训练大鼠中该比例为60.9±9.7%），但在游泳17 - 21小时后或游泳结束后立即测定时，血清总甲状腺素、游离甲状腺素或三碘甲状腺原氨酸的浓度并未升高。尽管体重与游泳大鼠相同但间歇性禁食的大鼠肌球蛋白V1比例降低（23.5±2.7），然而游泳大鼠的肌球蛋白V1比例仍升高。当游泳大鼠只能间歇性获取食物时，它们所有甲状腺激素的浓度均降低，但肌球蛋白V1的比例（51.5±7.6）仍增加。因此，肌球蛋白表达的重定向不能归因于甲状腺激素分泌增加。通过用β受体阻滞剂阿替洛尔治疗游泳大鼠来评估肾上腺素能系统的影响。由于肌球蛋白V1的比例降低，但甲状腺激素未受影响，β-肾上腺素能阻滞似乎独立于甲状腺激素影响肌球蛋白表达。
