Effect of dehydroepiandrosterone (DHEA) on calcio mobilization and hormonal secretion of normal pituitary cells in vitro

SUÁREZ CECILIA, VELA J, BECÚ-VILLALOBOS D

Tandil, Buenos Aires

Congreso; XXXIV Congreso de la Sociedad Argentina de Farmacología Experimental; 2002

SAFE

In a previous work we showed that DHEA in vivo was able to partially reverse dietilestilbestrol (DES)-induced pituitary hyperplasia, hyperprolactinemia and loss of body weight. The aim of this study was to determine the effects of DHEA on normal pituitary cells in vitro. Pituitary cells of 60-day old female rats were cultured and stimulated with DHEA, OH-DHEA, androstenediol, dopamine (DA) and GHRH. Alter 48 hs prolactin (PRL), growth hormona (GH) and luteinizing hormona (LH) secretion was measured by RIA. The intracellular calcium mobilization in a suspensión of cells stimulated with DA or GHRH in presence or absence of DHEA was also determined by the Fura-2AM fluorometric method. DHEA was able to significantly reduce the basal PRL secretion (31±8% for DHEA 10-7M) but also to reverse in a dose-dependent manner the PRL inhibition induced by DA. Accordingly, DHEA blocked the decrease in intracellular calcium mobilization achieved by DA. DHEA 10-7M increased GH secretion induced by GHRH (in a 34±13%) although this effect was not related with the intracellular calcium release induced by GHRH. We concluye that DHEA has direct in vitro effects that correspond with some of its endocrine actions in vivo.