Hypothalamic atrial natriuretic peptide secretion plasticity: Differential modulation of alpha and beta adrenoceptors

Abstract

Increasing evidence suggests that atrial natriuretic peptide (ANP), a 28-amino acid peptide with biologically active 4-28 and 5-28 congeners modulates salt-water homeostasis at both peripheral and central levels. In rats, immunoreactive (ir) ANP is found in hypothalamic (HT) neurons of preoptic and paraventricular regions rich in aminergic innervation. Employing a well-characterized perifusion model of rat HT explants, the acute effects of norepinephrine (NE) on HT release of irANP were examined. Pulsatile administration (20 min) of NE(10-7 to 10-5 M) induced a dose-related release of irANP. The stimulatory effect of 10-5 M NE (2.66 ± 0.54 pg/ml/HT, means ± SE, n = 12) was abolished in the p..