The renin-angiotensin system and nociception in the spontaneously hypertensive rat

Abstract

This study investigated the effects of captopril, hydralazine and losartan on the locomotor activity, tailflick and hot plate latencies in spontaneously hypertensive rats (SHR) and their genetic controls the Wistar-Kyoto rat (WKY). The increased hot plate latencies normally exhibited by the spontaneously hypertensive rat were reduced or abolished by captopril ( 95 mg/kg/day p.o.) and losartan (18 mg/kg/day p.o.) treatment, but were unaffected by hydralazine (19 mg/kg/day p.o.). There were no observable effects of any of the drugs on tailflick latencies or locomotor activity. The results highlight a potential role for angiotensin II in analgesia that is independent of blood pressure change.