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

De Koning, H. P./ , Jenks, B. G., Scheenen, W. J.J.M., Balm, P. H.M. and Roubos, E. W. (1992) Analysis of autofeedback mechanisms in the secretion of pro-opiomelanocortin-derived peptides by melanotrope cells of Xenopus laevis. General and Comparative Endocrinology, 87(3), pp. 394-401. (doi: 10.1016/0016-6480(92)90046-M)

Abstract

The secretion of most pituitary hormones is under the control of feedback mechanisms. The feedback control of α-melanophore-stimulating hormone (α-MSH) from melanotrope cells is controversial. The possible existence of an autofeedback exerted by α-MSH or other POMC-derived peptides on melanotrope cells of the amphibian Xenopus laevis has been investigated. α-MSH or its potent agonist 4-norleucine, 7-d-phenylalanine-α-MSH has no effect on the release of radiolabeled POMC-derived peptides or immunoreactive β-endorphin from superfused neurointermediate pituitary lobes. Melanin concentrating hormone, previously reported to have an α-MSH-like effect on melanophores, did not affect α-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 auto-feedback mechanisms involving α-MSH or other POMC-derived peptides.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: De Koning, Professor Harry
• Authors: De Koning, H. P./, Jenks, B. G., Scheenen, W. J.J.M., Balm, P. H.M., and Roubos, E. W.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: General and Comparative Endocrinology
• Publisher: Academic Press
• ISSN: 0016-6480
• ISSN (Online): 1095-6840