Côté C, Thibault M C, Valliéres J
Life Sci. 1985 Aug 26;37(8):695-701. doi: 10.1016/0024-3205(85)90538-7.
The purpose of this study was to determine the influence of metabolic stresses, such as endurance training and chronic isoproterenol treatment, on skeletal muscle sensitivity to norepinephrine. Using an isolated perfused rat hindlimb preparation, dose-response curves for skeletal muscle oxygen consumption (VO2) and vascular resistance were obtained with control, endurance trained, and isoproterenol treated rats. No significant difference was found between control and experimental groups for non-stimulated VO2. In response to NE infusion, trained rats showed a significantly greater increase in VO2 compared to control rats while the response of the isoproterenol treated rats was of the same magnitude as the one for their respective control rats. At the highest dose of NE infused, the vasopressor response was significantly lower in trained rats compared to control rats. At none of the doses was there a significant difference in the vasopressor response between control and isoproterenol treated rats. These results suggest that repeated exposures to high levels of catecholamines, as produced during endurance training, leads to an increased sensitivity of skeletal muscle to the effect of norepinephrine.
本研究的目的是确定耐力训练和慢性异丙肾上腺素治疗等代谢应激对骨骼肌去甲肾上腺素敏感性的影响。使用离体灌注大鼠后肢制备方法，获得了对照、耐力训练和异丙肾上腺素治疗大鼠的骨骼肌耗氧量（VO2）和血管阻力的剂量反应曲线。未刺激的VO2在对照组和实验组之间未发现显著差异。在输注去甲肾上腺素时，训练大鼠的VO2增加幅度显著大于对照大鼠，而异丙肾上腺素治疗大鼠的反应幅度与各自对照大鼠相同。在输注最高剂量的去甲肾上腺素时，训练大鼠的升压反应显著低于对照大鼠。在任何剂量下，对照大鼠和异丙肾上腺素治疗大鼠之间的升压反应均无显著差异。这些结果表明，如耐力训练期间产生的那样，反复暴露于高水平儿茶酚胺会导致骨骼肌对去甲肾上腺素作用的敏感性增加。
