Richter E A, Ruderman N B, Galbo H
Acta Physiol Scand. 1982 Nov;116(3):215-22. doi: 10.1111/j.1748-1716.1982.tb07133.x.
The role of alpha- and beta-adrenergic receptor stimulation for the effect of epinephrine on muscle glycogenolysis, glucose- and oxygen uptake and muscle performance was studied in the perfused rat hindquarter at rest and during electrical stimulation (60 contractions/min). Adrenergic stimulation was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect was mediated by alpha- as well as by beta-adrenergic stimulation, the latter involving production of cAMP, phosphorylase activation and synthase inactivation. In contrast, in fast-twitch fibers only beta-adrenergic mechanisms were involved in the glycogenolytic effect of epinephrine. Moreover, inactivation of synthase was less in these fibers. Epinephrine also increased the net release of lactate from the hindquarter, an effect abolished by combined alpha- and beta-adrenergic blockade but by neither alpha- nor beta-adrenergic blockade alone. Epinephrine increased uptake of oxygen and glucose by stimulation of alpha-adrenergic receptors and had a positive inotropic effect during contractions which was abolished by alpha- as well as by beta-adrenergic blockade. The results indicate that epinephrine has profound effects on contracting muscle, and that these effects are elicited through different combinations of alpha- and beta-adrenergic receptor stimulation.
研究了α-和β-肾上腺素能受体刺激对肾上腺素在静息和电刺激（60次收缩/分钟）时对灌注大鼠后肢肌肉糖原分解、葡萄糖和氧气摄取以及肌肉性能的影响。通过生理浓度（2.4×10⁻⁸ M）的肾上腺素实现肾上腺素能刺激，分别用10⁻⁵ M酚妥拉明和普萘洛尔进行α-和β-肾上腺素能阻断。肾上腺素在收缩过程中最显著地增强了慢肌红纤维中的净糖原分解。在这些纤维中，该效应由α-和β-肾上腺素能刺激介导，后者涉及cAMP的产生、磷酸化酶激活和合成酶失活。相比之下，在快肌纤维中，肾上腺素的糖原分解作用仅涉及β-肾上腺素能机制。此外，这些纤维中合成酶的失活较少。肾上腺素还增加了后肢乳酸的净释放，α-和β-肾上腺素能联合阻断可消除该效应，但单独的α-或β-肾上腺素能阻断均不能消除。肾上腺素通过刺激α-肾上腺素能受体增加氧气和葡萄糖的摄取，并在收缩过程中产生正性肌力作用，α-和β-肾上腺素能阻断均可消除该作用。结果表明，肾上腺素对收缩肌肉有深远影响，且这些影响是通过α-和β-肾上腺素能受体刺激的不同组合引发的。
