Angiotensin II and dopamine modulate both cAMP and inositol phosphate productions in anterior pituitary cells. Involvement in prolactin secretion.
Angiotensin II and dopamine modulate both cAMP and inositol phosphate productions in anterior pituitary cells. Involvement in prolactin secretion.
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血管紧张素 II 和多巴胺调节垂体前叶细胞中 cAMP 和磷酸肌醇的产生。
DOI：
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发表时间：
1986
影响因子：
4.8
通讯作者：
C. Kordon
中科院分区：
文献类型：
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作者：
A. Enjalbert;F. Sladeczek;G. Guillon;P. Bertrand;C. Shu;J. Epelbaum;A. García;S. Jard;C. Lombard;C. Kordon
尽管它们对催乳素分泌有相反的作用，但多巴胺和血管紧张素II都抑制原代培养的垂体前叶细胞匀浆中腺苷酸环化酶的活性。多巴胺和血管紧张素II抑制腺苷酸环化酶是不加和的，这表明这两种神经激素抑制催乳细胞的腺苷酸环化酶。用百日咳杆菌毒素（胰岛激活蛋白）预处理完全抑制了多巴胺诱导的腺苷酸环化酶和催乳素分泌的抑制。胰岛激活蛋白还逆转了血管紧张素II诱导的腺苷酸环化酶活性抑制。相反，血管紧张素II刺激催乳素释放不受毒素的影响。血管紧张素II还诱导肌醇磷酸（250%）的剂量依赖性刺激，EC50为0.1 nM，接近于观察到的催乳素分泌。胰岛激活蛋白预处理并不能阻断磷酸肌醇的产生。多巴胺抑制血管紧张素II刺激的催乳素释放和血管紧张素II诱导的肌醇磷酸的产生。它的结论是，血管紧张素II和多巴胺受体的催乳细胞能够调节cAMP和磷酸肌醇的生产。催乳素细胞的多巴胺受体似乎是第一个与肌醇磷酸的产生负偶联的受体的例子。
Despite their opposite effects on prolactin secretion, both dopamine and angiotensin II inhibit adenylate cyclase activity in homogenates of anterior pituitary cells in primary culture. Dopamine and angiotensin II inhibition of adenylate cyclase was not additive, suggesting that both neurohormones inhibit the adenylate cyclase of the lactotroph cells. Pretreatment with Bordetella pertussis toxin (islet activator protein) completely suppressed the dopamine-induced inhibition of both adenylate cyclase and prolactin secretion. The islet activator protein also reversed the angiotensin II-induced inhibition of the adenylate cyclase activity. In contrast, angiotensin II stimulation of prolactin release was not affected by the toxin. Angiotensin II also induced a dose-dependent stimulation of inositol phosphates (250%) with an EC50 of 0.1 nM, close to that observed for prolactin secretion. Islet activator protein pretreatment did not block the stimulation of inositol phosphate production. Dopamine inhibited the angiotensin II-stimulated prolactin release and the production of inositol phosphates induced by angiotensin II. It is concluded that angiotensin II and dopamine receptors of lactotroph cells are able to modulate both cAMP and inositol phosphate production. The dopamine receptor of lactotrophs appears to be the first example of a receptor which is negatively coupled to the production of inositol phosphates.