Reversal of angiotensin converting enzyme (ACE) inhibitor induced vasodilatation by vasopressin in hindquarters of rat.

ABSTRACT

The effect of exogenously administered vasopressin was observed on captopril induced vasodilatation in hindquarters of anaesthetised rats. Drops of perfusate were counted for 6 min and mean of the outflow was expressed as drops per min (dpm). In the control group (n = 6) the rate of flow was 9.5 +/- 1.04 dpm which increased to 12.33 +/- 1.36 dpm following captopril (200 micrograms/ml) infusion. In test group (n = 6) pretreated with vasopressin (4 I.U./kg 1 hr before) the rate of flow was 9.16 +/- 0.98 dpm which was reduced to 5.5 +/- 1.04 dpm following infusion with captopril. It is concluded that vasopressin reverses the vasodilatory effect of captopril.