Endocrinology, Vol 126, 3200-3203, Copyright © 1990 by Endocrine Society

ARTICLES

Glucocorticoids: potent inhibitors and stimulators of growth hormone secretion

WB Wehrenberg, BA Janowski, AW Piering, F Culler and KL Jones
Department of Health Sciences, University of Wisconsin-Milwaukee 53201.

Excessive glucocorticoid concentrations are well recognized inhibitors of linear growth, due in part to their suppression of GH secretion. The mechanism of this inhibition has been unclear, especially since glucocorticoids enhance the in vitro GH response of pituitary cells to GH-releasing hormone (GHRH). We investigated the possibility that hypothalamic somatostatin might be mediating these dichotomous observations by using passive immunization techniques. The GH response to GHRH was significantly blunted in rats pretreated with the synthetic glucocorticoid, dexamethasone, compared to that in normal animals. In marked contrast, the immunoneutralization of somatostatin resulted in a significantly enhanced GH response to GHRH in dexamethasone-treated animals. These results suggest that the previously described inhibitory action of glucocorticoids on GH secretion in vivo are mediated via altered hypothalamic somatostatin tone.

This article has been cited by other articles:

				G. Tulipano, D. Soldi, M. Bagnasco, M. D. Culler, J. E. Taylor, D. Cocchi, and A. Giustina Characterization of New Selective Somatostatin Receptor Subtype-2 (sst2) Antagonists, BIM-23627 and BIM-23454. Effects of BIM-23627 on GH Release in Anesthetized Male Rats after Short-Term High-Dose Dexamethasone Treatment Endocrinology, April 1, 2002; 143(4): 1218 - 1224. [Abstract] [Full Text] [PDF]

				E. E. Muller, V. Locatelli, and D. Cocchi Neuroendocrine Control of Growth Hormone Secretion Physiol Rev, April 1, 1999; 79(2): 511 - 607. [Abstract] [Full Text] [PDF]

				A. Giustina and J. D. Veldhuis Pathophysiology of the Neuroregulation of Growth Hormone Secretion in Experimental Animals and the Human Endocr. Rev., December 1, 1998; 19(6): 717 - 797. [Abstract] [Full Text]

				D. B. Allen, J. R. Julius, T. J. Breen, and K. M. Attie Treatment of Glucocorticoid-Induced Growth Suppression with Growth Hormone J. Clin. Endocrinol. Metab., August 1, 1998; 83(8): 2824 - 2829. [Abstract] [Full Text]

				C. Jux, K. Leiber, U. Hugel, W. Blum, C. Ohlsson, G. Klaus, and O. Mehls Dexamethasone Impairs Growth Hormone (GH)-Stimulated Growth by Suppression of Local Insulin-Like Growth Factor (IGF)-I Production and Expression of GH- and IGF-I-Receptor in Cultured Rat Chondrocytes Endocrinology, July 1, 1998; 139(7): 3296 - 3305. [Abstract] [Full Text] [PDF]

				T. L. Miller and K. E. Mayo Glucocorticoids Regulate Pituitary Growth Hormone-Releasing Hormone Receptor Messenger Ribonucleic Acid Expression Endocrinology, June 1, 1997; 138(6): 2458 - 2465. [Abstract] [Full Text] [PDF]

				G. B. Thomas, K. M. Fairhall, and I. C. A. F. Robinson Activation of the Hypothalamo-Pituitary-Adrenal Axis by the Growth Hormone (GH) Secretagogue, GH-Releasing Peptide-6, in Rats Endocrinology, April 1, 1997; 138(4): 1585 - 1591. [Abstract] [Full Text] [PDF]