Involvement of endothelins in DOCA-salt hypertension through the modulation of noradrenergic transmission in the rat posterior hypothalamus

TAMARA ABRAMOFF; MARIA JULIA GUIL; VANINA P MORALES; SANDRA I. HOPE; CHRISTIAN HOCHT; LILIANA G. BIANCIOTTI; MARCELO S. VATTA

EXPERIMENTAL PHYSIOLOGY.

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

0958-0670

Brain catecholamines participate in diverse biological functions regulated by the hypothalamus. We have previously reported that endothelin-1 and -3 (ET-1 and ET-3) modulate catecholaminergic activity in the anterior and posterior hypothalamus of normotensive rats. The aim of the present study was to evaluate the interaction between ETs and noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate (DOCA)-Salt hypertensive rats. We assessed the effects of ET-1 and ET-3 on tyrosine hydroxylase activity and expression, neuronal norepinephrine (NE) release, neuronal NE transporter (NET) activity and expression, monoamine oxidase activity, and NE endogenous content and utilization (as a marker of turn-over) in the posterior hypothalamus of DOCA-Salt hypertensive rats. Results showed that TH activity and total and phosphorylated levels, NET activity and content, NE release, monoamine oxidase activity, and NE utilization were increased in DOCA-Salt rats. Both ET-1 and ET-3 further enhanced all noradrenergic parameters except for total TH level, and NE endogenous content and utilization. Present results show that ET-1 and ET-3 up-regulate noradrenergic activity in the posterior hypothalamus of DOCA-Salt hypertensive rats. Our findings suggest that the interaction between noradrenergic transmission and the endothelinergic system in the posterior hypothalamus may be involved in the development or/and maintenance of hypertension in this animal model.