[Potentiative effects of angiotensin converting enzyme inhibitors on carrageenan-induced edema in rats].

Carrageenan-induced edema of rat paw was greatly potentiated by orally or locally administered angiotensin converting enzyme (CE, identical with kininase II) inhibitor, (4R)-3-[(2S)-3-mercapto-2-methylpropanoyl]-4-thiazolidinecarboxylic acid (YS980). The potentiative effect of YS980 was observed by the administration not only prior to but also 3 hr after the carrageenan injection. The vascular permeability test showed the same potentiative effect of YS980 in the inflamed tissue of carrageenan edema. Bradykinin potentiating peptide-B (BPP-B) and 1,10-phenanthroline also potentiated the edema and the effects of these compounds were in order of YS980 greater than BPP-B greater than 1,10-phenanthroline. The order was in accordance with that of inhibitory potencies against kininase II activity of rat serum in vitro. However, the activity of kininase I was not affected by YS980 and BPP-B. In addition, among various experimental models of acute paw edema, the potentiative effects of YS980 were restricted to the inflammations mediated by kinins such as carrageenan, cellulose sulfate, kaolin and bradykinin-induced edema. These results suggest that the potentiative effect of YS980 on carrageenan edema is mainly based on its inhibitory effect on kininase II in the inflamed site.