RELEASE OF H-3 NORADRENALINE FROM THE RAT OVIDUCT - CHANGES DURING ESTROUS-CYCLE AND BY PROGESTERONE INVITRO

CHIAPPE, P; GALLEGUILLOS, X; LARA, H; FUENTEALBA, B; FORRAY, I; BELMAR, J

RELEASE OF H-3 NORADRENALINE FROM THE RAT OVIDUCT - CHANGES DURING ESTROUS-CYCLE AND BY PROGESTERONE INVITRO

Date

1990

Authors

Abstract

Rat oviduct noradrenergic innervation seems to be under the influence of hormonal modulation. Noradrenaline level is specifically affected, but other processes like the release of the neurotransmitter have not yet been studied. In this work the release of 3H-noradrenaline (3H-NA) during the estrous cycle and its modification by progesterone "in vitro", were studied. The basal 3H-NA outflow was unchanged during the estrous cycle. However, the induced release (K+, 80 mM) was maximal during estrous. After progesterone, induced 3H-NA release was inhibited at low concentrations (5 .mu.M); under higher concentrations (50 .mu.M) the effect persisted but basal outflow of radioactivity was increased. The inhibitory effect was potentiated by RU-486 (Progesterone blocker). Results suggest a modulatory role for the hormone and it could be related to interactions with nerve-ending membranes and not with classical nuclear receptors.