the effect of quinapril on the aortic contractile response of streptozotocin-diabetic rats

angiotensin-converting enzyme (ace) inhibitors appear to correct many of the abnormalities associated with the vascular dysfunction found in diabetic patients. in this respect, quinapril is a unique ace inhibitor with multiple protective effects. the present study was carried out to investigate the effect of intraperitoneal administration of quinapril on the aortic reactivity of streptozotocin (stz)-diabetic rats. for this purpose, male wistar rats received one injection of streptozotocin (stz), 60 mg/kg, to induce diabetes. three days after stz injection, rats were treated with quinapril (2 mg/kg/day) for 4 weeks, after that aortic reactivity to vasoactive agents were compared with those of untreated diabetic rats or non-diabetic control rats. for this purpose, contractile response to phenylephrine (pe) was obtained from aortic rings. concentration-response curves from quinapril-treated diabetic rats to pe in the presence and absence of endothelium were attenuated as compared to vehicle-treated diabetics. therefore, the 4-week treatment of diabetic rats with quinapril could prevent the functional changes in vascular reactivity in diabetic rats