肾上腺素能受体对大鼠血小板中凝血酶诱导的磷酸肌醇代谢的影响。

Influence of adrenoceptors on thrombin-induced phosphoinositide metabolism in rat platelets.

作者信息

Koutouzov S, Cothenet-Vernoux L, Dausse J P, Marche P

出版信息

Biochem Biophys Res Commun. 1985 Nov 15;132(3):1051-8. doi: 10.1016/0006-291x(85)91913-8.

DOI:10.1016/0006-291x(85)91913-8

Abstract

Stimulation of washed rat platelets with thrombin resulted in an increased turnover of phosphoinositides. Adrenaline and isoproterenol both inhibited thrombin-induced phosphatidic acid formation in a dose-dependent manner. Inhibitory responses of both compounds were blocked by a beta-adrenoceptor antagonist. However, isoproterenol was a more potent inhibitor than adrenaline. Addition of a selective alpha2-adrenoceptor antagonist potentiated the inhibitory effect of adrenaline up to the level observed with isoproterenol. Prestimulation of beta-adrenoceptors with isoproterenol, followed by addition of adrenaline (or noradrenaline) markedly diminished the inhibitory effect induced by the full beta-adrenoceptor agonist. Our results indicate that, in rat platelets, catecholamines are able to counteract, via alpha2-receptors, the beta-adrenoceptor-mediated inhibition of thrombin-induced phosphatidic acid formation. This suggests that catecholamines, by controlling cAMP level, may modulate phospholipase C activity and thereby platelet reactivity.

摘要

用凝血酶刺激洗涤过的大鼠血小板会导致磷酸肌醇周转率增加。肾上腺素和异丙肾上腺素均以剂量依赖的方式抑制凝血酶诱导的磷脂酸形成。两种化合物的抑制反应均被β-肾上腺素能受体拮抗剂阻断。然而，异丙肾上腺素是比肾上腺素更有效的抑制剂。添加选择性α2-肾上腺素能受体拮抗剂可将肾上腺素的抑制作用增强至与异丙肾上腺素观察到的水平。先用异丙肾上腺素预刺激β-肾上腺素能受体，然后添加肾上腺素（或去甲肾上腺素），可显著减弱完全β-肾上腺素能受体激动剂诱导的抑制作用。我们的结果表明，在大鼠血小板中，儿茶酚胺能够通过α2受体抵消β-肾上腺素能受体介导的对凝血酶诱导的磷脂酸形成的抑制作用。这表明儿茶酚胺通过控制环磷酸腺苷水平，可能调节磷脂酶C活性，从而调节血小板反应性。