Endogenous kappa opioid receptors play a role in angiotensin II high salt diet hypertensive rats (860.24)

Abstract

Central kappa opioid receptor (KOR) activation produces a marked increase in renal sympathetic nerve activity with a concurrent free water diuresis in conscious rats. However, the role of KOR in the angiotensin II high salt diet (AngII) mediated hypertension model is yet to be determined. This study examines cFOS expression in several brain regions of AngII rats as compared to normal rats. In addition, cFos expression in these brain regions was examined following intracerebroventricular (ICV) microinjection of norbinaltorphimine (Nor‐BNI; 1 μg/5μl), a selective KOR antagonist. Alternate sets of forebrain sections were processed for c‐Fos using a commercially available antibody. Sections were also double labeled with vasopressin to anatomically define specific brain regions. Fos expression was significantly increased in several lamina terminalis and hypothalamic sites. ICV nor‐BNI produced significant decreases in cFos staining in the PVN (AngII, 106 ± 12; nor‐BNI 62 ± 7; P < .01) and OVLT (AngII, 132 ± 7; nor‐BNI 73 ± 5; P < .05). There was no significant change in urine and sodium excretion in all groups. Altogether, this data provides new information concerning the role of KOR in the regulation of blood pressure Grant Funding Source: 5SC2HL104639‐03