Henley J M
Mol Pharmacol. 1985 Nov;28(5):431-5.
The epinephrine-stimulated maintained increase in 86Rb efflux from guinea pig hepatocytes may consist of both alpha 1- and alpha 2-adrenoceptor-mediated components. Both the alpha 1-selective adrenoceptor agonist phenylephrine and the alpha 2-selective agonist clonidine evoked a maintained increase in 86Rb efflux. Prazosin, an alpha 1-selective antagonist, did not inhibit the maintained increase in 86Rb efflux elicited by epinephrine, whereas yohimbine, an alpha 2-selective antagonist, did. In the absence of external Ca, no maintained increase in 86Rb efflux was observed. The results suggest that there may be two separate alpha-adrenergic sensitive Ca influx pathways into guinea pig hepatocytes, one mediated by alpha 1- and the other by alpha 2-adrenoceptor activation.
肾上腺素刺激引起的豚鼠肝细胞86Rb外流持续增加可能由α1和α2肾上腺素能受体介导的成分共同组成。α1选择性肾上腺素能受体激动剂去氧肾上腺素和α2选择性激动剂可乐定均可引起86Rb外流持续增加。α1选择性拮抗剂哌唑嗪不抑制肾上腺素引起的86Rb外流持续增加，而α2选择性拮抗剂育亨宾则可以抑制。在无细胞外钙的情况下，未观察到86Rb外流持续增加。结果表明，可能存在两条独立的α-肾上腺素能敏感钙内流途径进入豚鼠肝细胞，一条由α1介导，另一条由α2肾上腺素能受体激活介导。
