STRESS-INDUCED REGULATION OF THE RENAL PERIPHERAL BENZODIAZEPINE RECEPTOR - POSSIBLE ROLE OF THE RENIN-ANGIOTENSIN SYSTEM

The etiology of the decrease in renal peripheral benzodiazepine recept or (PBR) binding caused by stress was studied in rats. Prior investiga tions suggest that the response of the renal PBR to stress occurs inde pendently of the hypothalamo-pituitary-adrenal (HPA) axis and sympathe tic nervous system. The present experiments tested the hypothesis that the renin-angiotensin system is involved in regulating the PBR. Eight y min of brief, intermittent tailshocks caused increases in plasma ren in activity and decreases in renal PBR binding. The stress-induced dec rease in renal PBR binding was reversed by pretreatment with captopril . Acute admininstration of angiotensin II (ANG II) alone caused reduct ions in PBR binding in kidney, heart, and cerebral cortex. These data suggest that ANG II may be an endogenous factor responsible for regula ting the PBR in several tissues during stress.