Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.

This study was designed to investigate the feedback loop between insulin-like growth factor-I (IGF-I) and IGF-II and the hypothalamic hormones growth hormone-releasing hormone (GHRH) and somatostatin (SS) using an in vitro rat hypothalamic model. IGF-I and, to lesser extent, IGF-II, both activate ty...

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Main Authors: Korbonits, M, Little, J, Camacho-Hübner, C, Trainer, P, Besser, G, Grossman, AB
Format: Journal article
Language:English
Published: 1996
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author Korbonits, M
Little, J
Camacho-Hübner, C
Trainer, P
Besser, G
Grossman, AB
author_facet Korbonits, M
Little, J
Camacho-Hübner, C
Trainer, P
Besser, G
Grossman, AB
author_sort Korbonits, M
collection OXFORD
description This study was designed to investigate the feedback loop between insulin-like growth factor-I (IGF-I) and IGF-II and the hypothalamic hormones growth hormone-releasing hormone (GHRH) and somatostatin (SS) using an in vitro rat hypothalamic model. IGF-I and, to lesser extent, IGF-II, both activate type 1 IGF receptors, while type 2 receptors are activated by IGF-II alone. IGF-I, IGF-II, their various specific analogues (Des[1-3]IGF-I, [Arg54/Arg55]IGF-II and [Leu27]IGF-II), insulin and the type 2 receptor antagonist beta-galactosidase were used on their own or in combination to study their effect on GHRH and SS release. Our results suggest that the simultaneous activation of type 1 and type 2 IGF receptors is needed for the negative feedback effect of IGFs on GHRH release in this in vitro system, in agreement with earlier findings in vivo. Somatostatin was not altered by any combination of peptides.
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spelling oxford-uuid:9ad7f2cc-bd2f-4964-9d83-b04aae0236072022-03-27T00:24:08ZInsulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9ad7f2cc-bd2f-4964-9d83-b04aae023607EnglishSymplectic Elements at Oxford1996Korbonits, MLittle, JCamacho-Hübner, CTrainer, PBesser, GGrossman, ABThis study was designed to investigate the feedback loop between insulin-like growth factor-I (IGF-I) and IGF-II and the hypothalamic hormones growth hormone-releasing hormone (GHRH) and somatostatin (SS) using an in vitro rat hypothalamic model. IGF-I and, to lesser extent, IGF-II, both activate type 1 IGF receptors, while type 2 receptors are activated by IGF-II alone. IGF-I, IGF-II, their various specific analogues (Des[1-3]IGF-I, [Arg54/Arg55]IGF-II and [Leu27]IGF-II), insulin and the type 2 receptor antagonist beta-galactosidase were used on their own or in combination to study their effect on GHRH and SS release. Our results suggest that the simultaneous activation of type 1 and type 2 IGF receptors is needed for the negative feedback effect of IGFs on GHRH release in this in vitro system, in agreement with earlier findings in vivo. Somatostatin was not altered by any combination of peptides.
spellingShingle Korbonits, M
Little, J
Camacho-Hübner, C
Trainer, P
Besser, G
Grossman, AB
Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title_full Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title_fullStr Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title_full_unstemmed Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title_short Insulin-like growth factor-I and- II in combination inhibit the release of growth hormone-releasing hormone from the rat hypothalamus in vitro.
title_sort insulin like growth factor i and ii in combination inhibit the release of growth hormone releasing hormone from the rat hypothalamus in vitro
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