AJP - Endocrinology and Metabolism, Vol 266, Issue 2 E274-E278, Copyright © 1994 by American Physiological Society

ARTICLES

Effects of LHRH and ANG II on prolactin stimulation are mediated by hypophysial AT1 receptor subtype

D. Becu-Villalobos, I. M. Lacau-Mengido, S. M. Thyssen, G. S. Diaz-Torga and C. Libertun
Laboratorio de Neuroendocrinologia, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires, Argentina.

We have used the nonpeptide angiotensin II (ANG II) receptor antagonists losartan (receptor subtype AT1) and PD-123319 (AT2) to determine the participation of ANG II receptor subtypes in luteinizing hormone-releasing hormone (LHRH)-induced prolactin release in a perifusion study using intact pituitaries in vitro. LHRH (1.85 x 10(-7) M) released prolactin consistently, whereas losartan (10(-5) M) abolished prolactin response without modifying basal prolactin or luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. PD-123319 (10(-5) M) had no effect on basal or LHRH-induced prolactin, LH, or FSH release. We also determined that the effect of ANG II on prolactin release was mediated by the same receptor subtype. In adenohypophysial cells dispersed in vitro ANG II (10(-8) M) released prolactin. Losartan (10(-7) and 10(-6) M), but not PD-123319, inhibited this effect. We conclude that in intact hypophyses of 15-day-old female rats the effect of LHRH on prolactin release is readily demonstrated. LHRH-induced prolactin release appears to be mediated by ANG II acting in a paracrine manner on AT1 receptors located on lactotrophs.

This article has been cited by other articles:

				C. Suarez, G. Diaz-Torga, A. Gonzalez-Iglesias, C. Cristina, and D. Becu-Villalobos Upregulation of angiotensin II type 2 receptor expression in estrogen-induced pituitary hyperplasia Am J Physiol Endocrinol Metab, May 1, 2004; 286(5): E786 - E794. [Abstract] [Full Text] [PDF]

				A. Gonzalez Iglesias, C. Suarez, C. Feierstein, G. Diaz-Torga, and D. Becu-Villalobos Desensitization of angiotensin II: effect on [Ca2+]i, inositol triphosphate, and prolactin in pituitary cells Am J Physiol Endocrinol Metab, March 1, 2001; 280(3): E462 - E470. [Abstract] [Full Text] [PDF]

				M. de Gasparo, K. J. Catt, T. Inagami, J. W. Wright, and Th. Unger International Union of Pharmacology. XXIII. The Angiotensin II Receptors Pharmacol. Rev., September 1, 2000; 52(3): 415 - 472. [Abstract] [Full Text] [PDF]

				G. Diaz-Torga, A. G. Iglesias, R. Achaval-Zaia, C. Libertun, and D. Becu-Villalobos Angiotensin II-induced Ca2+ mobilization and prolactin release in normal and hyperplastic pituitary cells Am J Physiol Endocrinol Metab, March 1, 1998; 274(3): E534 - E540. [Abstract] [Full Text] [PDF]

				O. Johren, G. L. Sanvitto, G. Egidy, and J. M. Saavedra Angiotensin II AT1A Receptor mRNA Expression Is Induced by Estrogen-Progesterone in Dopaminergic Neurons of the Female Rat Arcuate Nucleus J. Neurosci., November 1, 1997; 17(21): 8283 - 8292. [Abstract] [Full Text] [PDF]