Role of central angiotensinergic mechanism in shaking stress-induced ACTH and catecholamine secretion

Abstract

The role of central angiotensin II (AII) in the shaking stress-induced adrenocorticotropic hormone (ACTH), plasma catecholamine secretion and pressor response were investigated using conscious rats. We also studied whether or not vasopressin (VP) is involved in the shaking stress-induced pressor response. The shaking stress caused significant elevations in plasma ACTH, catecholamine, and systolic blood pressure. Intra-third ventricular administration of the AII antagonist, Sar 1, Ile 8-angiotensin II (saralasin) significantly attenuated pressor response and plasma noradrenaline elevation but not plasma ACTH elevation. Pretreatment with the vascular-type VP receptor (V1) antagonist, d(CH 2) 5Tyr(Me)AVP, did not attenuate pressor response nor plasma catecholamine elevation. These results indicate that the central angiotensinergic pathway at least partly mediates the shaking stress-induced activation of the sympathetic nervous system without VP involvement, and that central AII does not mediate the ACTH secretion evoked by shaking stress.