Vascular effects of epinephrine, lisinopril, and chlorpromazine in diabetic and non-diabetic rats

In this study, the vascular responses of diabetic rat femoral arteries to e pinephrine were investigated. The effects of lisinopril (ACE inhibitor) on vascular epinephrine sensitivity were also tested in a different group. Thi s study was carried out in sodium pentobarbital-anesthetized rats 8 weeks a fter induction of diabetes with streptozotocin. After extensive dissection of the femoral arteries with adventitial stripping, epinephrine and chlorpr omazine were applied to the vascular wall, and their vascular effects were compared in streptozotocin-diabetic (STZ-D), lisinopril-administered strept ozotocin-diabetic (LASTZ-D), lisinopril-administered nondiabetic (LAND), an d non-diabetic (ND) groups. Vasoconstriction was induced by epinephrine in all groups in a dose-response fashion. There were statistically significant differences in maximum percent constriction between STZ-D and LASTZ-D grou ps. There was also a significant increase in sensitivitity to epinephrine i n the STZ-D group. The vasoconstriction induced by epinephrine was relieved by chlorpromazine in all groups. Results suggest that there are important functional abnormalities in the re sponses of vessels to epinephrine in diabetics, and that the attenuation of vasoconstriction by ACE inhibitors may have benefical effects in microsurg ical procedures performed on diabetic patients. Topically-applied chlorprom azine appears to be effective in relieving vasospasm due to epinephrine, an d may be a useful tool to resolve perioperative vascular spasm in microsurg ical procedures for diabetic and non-diabetic patients.