Effects of brain natriuretic peptide on pituitary-adrenal activation in rats

The aim of this study was to characterize the effects of brain natriuretic peptide (BNP) on the hypothalamo-pituitary-adrenal (HPA) responses to diffe rent stress paradigms (ether stress, electric shock and restraint). Rats we re subjected to the stressful stimuli after intracerebroventricular adminis tration of BNP (32.5 ng - 6.5 mu g) and plasma corticosterone was used as a n indicator of the HPA activation. BNP did not modify the basal secretion, but inhibited the stress-induced rise in plasma corticosterone in a dose-de pendent manner. BNP proved most effective in decreasing the corticosterone response to ether stress and attenuated the electric shock and restraint-in duced HPA activation to a lesser extent. These results confirm the view tha t BNP takes part in the regulation of the HPA system.