THE EFFECT OF ACUTE ETHANOL (ETOH) EXPOSURE ON PROTEIN-KINASE-C (PKC)ACTIVITY IN ANTERIOR-PITUITARY

Alterations in the protein kinase C (PKC) pathway may interupt anterio r pituitary luteinizing hormone (LH) synthesis and/or secretion, which may impair normal reproductive function. Work by our laboratory and o thers has shown that EtOH has profound deleterious effects on the regu lation of the hypothalamic-pituitary-gonadal (HPG) axis. The present s tudy focuses on PKC translocation from the cytosol to the membrane of anterior pituitary after acute EtOH exposure. Serum levels of LH were measured at three time points (15, 30, and 90 min) after an TP injecti on of either saline or 3 g/kg EtOH in adult castrated male rats. LH le vels dropped significantly (p < 0.03) in EtOH-injected compared to sal ine-injected control animals. In the same animals, EtOH significantly suppressed PKC localization at its active site at the pituitary cell m embrane (p < 0.05). These findings suggest that the mechanism of EtOH' s suppression of LH is mediated, at least in part, through a decrease in PKC translocation to the anterior pituitary cell membrane. (C) 1997 Elsevier Science Inc.