单次游泳训练的大鼠分离出的右心房对异丙肾上腺素和肾上腺素的超敏反应。

Supersensitivity to isoprenaline and epinephrine in right atria isolated from rats submitted to a single swimming session.

Spadari R C, Bassani R A, De Moraes S

Department of Physiology and Biophysics, Universidade Estadual de Campinas (UNICAMP), SP, Brazil.

Gen Pharmacol. 1988;19(1):129-35. doi: 10.1016/0306-3623(88)90018-3.

Abstract

The effects of swim-induced stress on rat atrial norepinephrine content, plasma corticosterone level and pacemaker sensitivity to catecholamines were studied. 2. Swimming for 50 min reduced the atrial norepinephrine content and induced a long-lasting increase in the plasma corticosterone level. 3. Pacemakers isolated from swim stressed rats showed supersensitivity to the chronotropic effect of isoprenaline. Sensitivity to norepinephrine was not significantly altered. Bilateral adrenalectomy or metyrapone pretreatment prevented the development of swimming-induced supersensitivity to isoprenaline. After in vitro denervation and addition of cocaine supersensitivity to epinephrine was demonstrated. 4. It is concluded that corticosterone, at least partially, mediates the supersensitivity to isoprenaline and epinephrine in pacemaker isolated from acutely swim stressed rats.

摘要

研究了游泳诱导的应激对大鼠心房去甲肾上腺素含量、血浆皮质酮水平以及起搏器对儿茶酚胺敏感性的影响。2. 游泳50分钟可降低心房去甲肾上腺素含量，并使血浆皮质酮水平持久升高。3. 从经游泳应激的大鼠分离出的起搏器对异丙肾上腺素的变时作用表现出超敏感性。对去甲肾上腺素的敏感性无明显改变。双侧肾上腺切除术或甲吡酮预处理可防止游泳诱导的对异丙肾上腺素超敏感性的发展。体外去神经支配并添加可卡因后，对肾上腺素的超敏感性得以证明。4. 得出结论，皮质酮至少部分介导了从急性游泳应激大鼠分离出的起搏器对异丙肾上腺素和肾上腺素的超敏感性。