help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Enjalbert, A.
Right arrow Articles by Kordon, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Enjalbert, A.
Right arrow Articles by Kordon, C.

Endocrinology, Vol 111, 42-47, Copyright © 1982 by Endocrine Society

ARTICLES

Reciprocal interactions of somatostatin with thyrotropin-releasing hormone and vasoactive intestinal peptide on prolactin and growth hormone secretion in vitro

A Enjalbert, J Epelbaum, S Arancibia, L Tapia-Arancibia, MT Bluet-Pajot and C Kordon

Reciprocal interactions of somatostatin (SRIF) and vasoactive intestinal peptide (VIP) or TRH on in vitro PRL and GH release from male rats hemipituitaries were investigated. SRIF did not modify basal PRL release, but TRH- or VIP-induced release was inhibited by SRIF in a dose-dependent manner [effective concentration-fifty (EC50) = 1.7 +/- 0.9 nM for SRIF inhibition of TRH stimulation and EC50 = 0.8 +/- 0.5 nM for SRIF inhibition of VIP stimulation]. VIP and TRH did not affect GH release by themselves, but reduced the inhibition of GH secretion elicited by SRIF (EC50 = 7.6 +/- 3.4 nM for TRH blockade of SRIF inhibition and EC50 = 4.6 +/- 3.1 nM for VIP blockade of SRIF inhibition). Secretin, a partial structural analog of VIP, also blocked SRIF-induced inhibition of GH and stimulated PRL release. Secretin stimulation of PRL release was also prevented by SRIF. [D-Trp8,D- Cys14]SRIF, a potent analog of SRIF, antagonized VIP stimulation of PRL secretion with the same apparent affinity as the native peptide. The maximal stimulation, but not the apparent affinity of VIP action on prolactin release was reduced by SRIF, suggesting that the interaction is of a noncompetitive nature. This conclusion as further substantiated by the observation that neither TRH nor VIP were able to displace specific 125I-labeled [Tyr1] SRIF high affinity binding to pituitary membranes. The three peptides tested thus appear to exhibit reciprocal interactions mediated by independent receptor sites on GH as well as on PRL-producing cells.


This article has been cited by other articles:


Home page
 Physiol. Rev.Home page
M. E. Freeman, B. Kanyicska, A. Lerant, and G. Nagy
Prolactin: Structure, Function, and Regulation of Secretion
Physiol Rev, October 1, 2000; 80(4): 1523 - 1631.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1982 by The Endocrine Society