Williams R S, Schaible T F, Bishop T, Morey M
J Mol Cell Cardiol. 1984 May;16(5):395-403. doi: 10.1016/s0022-2828(84)80611-2.
To test the hypothesis that alterations in adrenergic or cholinergic receptors occur in response to physical training, and that changes in receptor properties could be mechanistically important in producting the altered cardiovascular physiology of the trained state, we studied the effects of endurance training by swimming upon beta adrenergic, alpha adrenergic, and muscarinic cholinergic receptors of rat heart. Because of previously reported sex-related differences in the cardiac adaptation to training, male and female rats were studied separately. Despite the occurrence of demonstrable training bradycardia in males, and of cardiac hypertrophy in females, there were no discernible effects of the training program upon the properties of cardiac beta adrenergic receptors. However, hearts from swimmers of both sexes demonstrated fewer numbers of muscarinic cholinergic and alpha adrenergic receptors than sedentary controls, without differences in the receptor affinities for antagonist or agonist compounds. These findings are inconsistent with the hypothesis that altered cardiac sensitivity to neurotransmitters contributes directly to training bradycardia.
为了验证肾上腺素能或胆碱能受体的改变是对体育锻炼的响应，以及受体性质的变化在产生训练状态下心血管生理改变方面可能具有重要机制这一假说，我们研究长跑训练对大鼠心脏β - 肾上腺素能、α - 肾上腺素能以及毒蕈碱胆碱能受体的影响。鉴于先前报道中有关心脏对训练适应性方面存在性别差异，我们分别对雄性和雌性大鼠进行了研究。尽管雄性大鼠出现了明显的训练性心动过缓，雌性大鼠出现了心脏肥大，但训练方案对心脏β - 肾上腺素能受体的性质并未产生明显影响。然而，与久坐不动的对照组相比，两性游泳大鼠心脏中的毒蕈碱胆碱能受体和α - 肾上腺素能受体数量均减少，且受体对拮抗剂或激动剂化合物的亲和力并无差异。这些发现与心脏对神经递质敏感性改变直接导致训练性心动过缓的假说不一致。
