Both nicotinic and muscarinic receptors mediate catecholamine secretion by isolated guinea-pig chromaffin cells
Both nicotinic and muscarinic receptors mediate catecholamine secretion by isolated guinea-pig chromaffin cells
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烟碱和毒蕈碱受体介导分离的豚鼠嗜铬细胞分泌儿茶酚胺
DOI：
10.1016/0306-4522(83)90236-1
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发表时间：
1983
期刊：
影响因子：
3.3
通讯作者：
R. Perlman
中科院分区：
文献类型：
--
作者：
L. Role;R. Perlman
We have studied the roles of nicotinic and muscarinic receptors in the acetylcholine-evoked secretion of catecholamine from guinea-pig chromaffin cells. Isolated guinea-pig chromaffin cells secrete catecholamine in response to acetylcholine, nicotine, and a variety of muscarinic agonists. Optimal concentrations of acetylcholine (50–200 μM) induce the release of 10–25% of the catecholamine content of the cells in 10 min. Maximal secretion evoked by nicotine or by muscarinic agonists is 5–12% of the catecholamine content of the cells. Secretion evoked by optimal concentrations of nicotine (50 μM) and muscarine (200 μM) are additive, and together these agonists cause catecholamine release equivalent to that produced by optimal concentrations of acetylcholine. Atropine causes a biphasic inhibition of acetylcholine-induced catecholamine secretion; low concentrations of atropine (0.02–0.1 μM) inhibit by 35–45% the catecholamine secretion evoked by 100 μM acetylcholine. Increasing the atropine concentration from 0.1 to 5 μM causes no further decrease in acetylcholine-evoked release, but at concentrations above 5 μM, a second distinct phase of inhibition appears. At 100 μM, atropine reduces acetylcholine-evoked secretion by 85%. At 0.1 μM, atropine significantly inhibits secretion induced by muscarinic, but not nicotinic, agonists. Tubocurarine (50 μM) does not block muscarinic stimulation of release, but inhibits acetylcholine- and nicotine-evoked release by 70 and 80%, respectively.Our experiments indicate that nicotinic and muscarinic stimulation represent distinct mechanisms for the activation of catecholamine release from guinea-pig chromaffin cells. Acetylcholine causes secretion by both of these pathways. Nicotinic stimulation accounts for approximately 60–70% of the release caused by 100 μM acetylcholine; the remaining 30–40% of the acetylcholine-evoked release is mediated by muscarinic receptors.
