Effect of captopril on angiotensin II release from vascular tissues in rats.

Isolated rat hindlegs were perfused with Krebs-Ringer solution and released angiotensin I (ANG I) and ANG II were determined. The release of ANG I and ANG II in nephrectomized rats did not differ from those in control group. Pretreatment with captopril (50 mg/kg/day) for 3 days or addition of captopril (2 X 10(-6) M) to the perfusate induced increase in ANG I release and decrease in ANG II release. These findings suggest that ANG II is locally generated and release from the vascular tissues. Captopril may inhibit the conversion of vascular ANG I into ANG II.