Activity of the angiotensin converting enzyme (ACE) in male and female rats. ACE activity in the ventral mesencephalon of males and female rats with estrogen (ovx +E2). ACE activity was significantly higher in male rats. Data were obtained as nmoles of his-leu produced per milligram of protein per minute and the results were then normalized to the values for ovx+E2 females (100%). Data are means ± SEM. *p < 0.05 (Student's t test).