非洲爪蟾促黑素细胞分泌阿片-促黑素-促皮质素原衍生肽的自动反馈机制分析

Analysis of autofeedback mechanisms in the secretion of pro-opiomelanocortin-derived peptides by melanotrope cells of Xenopus laevis.

作者信息

de Koning H P, Jenks B G, Scheenen W J, Balm P H, Roubos E W

机构信息

Department of Animal Physiology, Faculty of Science, University of Nijmegen, The Netherlands.

出版信息

Gen Comp Endocrinol. 1992 Sep;87(3):394-401. doi: 10.1016/0016-6480(92)90046-m.

DOI:10.1016/0016-6480(92)90046-m

PMID:1330808

Abstract

The secretion of most pituitary hormones is under the control of feedback mechanisms. The feedback control of alpha-melanophore-stimulating hormone (alpha-MSH) from melanotrope cells is controversial. The possible existence of an autofeedback exerted by alpha-MSH or other POMC-derived peptides on melanotrope cells of the amphibian Xenopus laevis has been investigated. alpha-MSH or its potent agonist 4-norleucine,7-D-phenylalanine-alpha-MSH has no effect on the release of radiolabeled POMC-derived peptides or immunoreactive beta-endorphin from superfused neurointermediate pituitary lobes. Melanin concentrating hormone, previously reported to have an alpha-MSH-like effect on melanophores, did not affect alpha-MSH secretion. Neurointermediate lobe superfusate, which contains a mixture of POMC-derived peptides, failed to affect the secretory activity of melanotropes. It is concluded that in X. laevis the secretory activity of melanotropes is not under the control of short-term autofeedback mechanisms involving alpha-MSH or other POMC-derived peptides.

摘要

大多数垂体激素的分泌受反馈机制的控制。促黑素细胞激素（α-MSH）对促黑素细胞的反馈控制存在争议。人们已经研究了α-MSH或其他源自阿黑皮素原（POMC）的肽对非洲爪蟾促黑素细胞施加自身反馈的可能性。α-MSH或其强效激动剂4-去甲亮氨酸，7-D-苯丙氨酸-α-MSH对经超灌注的神经垂体中间叶释放放射性标记的源自POMC的肽或免疫反应性β-内啡肽没有影响。先前报道对黑素细胞有α-MSH样作用的黑素浓缩激素，并不影响α-MSH的分泌。含有源自POMC的肽混合物的神经垂体中间叶超滤液，未能影响促黑素细胞的分泌活性。得出的结论是，在非洲爪蟾中，促黑素细胞的分泌活性不受涉及α-MSH或其他源自POMC的肽的短期自身反馈机制的控制。