Inhibition of vascular permeability changes in rats by captopril.

A B S T R A C T Systemic treatment of rats with cap- topril (50 mg/kg body wt per os), a specific compet- itive inhibitor of angiotensin 1-converting enzyme, sig- nificantly inhibits vascular permeability changes induced by the intradermal injection of the vasoactive mediators histamine, bradykinin, serotonin, and com- pound 48/80. This effect of captopril is both doseand time-dependent with '60% inhibition of edema for- mation observed 7 h after captopril treatment (100 mg/kg bpdy wt per os). The inhibitory effect of cap- topril on edema formation is temporally unrelated to the inhibition of serum angiotensin 1-converting enzyme activity or serum prostaglandin E2 levels and is not inhibited by systemic treatment of rats with in- domethacin. The data suggest that captopril may have potent antiinflammatory activity through as yet un- defined mechanisms.