Abstract

 

Renin-angiotensin system is thought to be modulated by gonadal steroids. However, it has not been well established whether gonadal steroids also modulate the changes in plasma renin activity (PRA) occuring in response to stimuli such as acute renal ischemia and also the effects of angiotensin-converting enzyme (ACE) on PRA. The aim of the present experiment was to study the relationship between sex hormones and plasma renin activity during acute renal ischemia in the Wistar rats. For this purpose, ovariectomy was performed in some rats and the changes in PRA in response to acute renal ischemia were observed. The levels of serum aldosterone and electrolytes were also measured. Ovariectomy not only caused a decrease in PRA but also reduced PRA response to acute renal ischemia. In contrast, ovariectomy had a reverse effect increasing PRA activity when ramipril, an ACE inhibitor, was used to prevent excessive angiotensin II formation due to renal ischemia. In conclusion, it can be said that gonadal steroids may have a role in modulating the PRA response to acute renal ischemia and may lead to changes in the effect of ACE inhibitors.

Key words: Ovariectomy, plasma renin activity, renal ischemia.