Inhibition of pressor effects of angiotensin I and augmentation of depressor effects of bradykinin by synthetic peptides.

SummarySeven synthetic peptides that correspond to compounds found in the venom of Bothrops jararaca were studied in normo-tensive, urethanized rats infused with pen-tolinium. When administered stat iv, the peptides inhibited pressor responses induced by angiotensin I but not those induced by angiotensin II. This activity was most likely the result of inhibition of angiotensin-converting enzyme. The peptides appeared to differ from each other with respect to potency and duration of action. The 3 test peptides injected im and sc displayed rapid, effective absorption by those routes.Three peptides tested stat iv in normoten-sive; urethanized rats augmented the vasodepressor effect of bradykinin to different degrees.