RESUMO
The venom of the Brazilian snake Bothrops jararacussu, was found to contain peptides capable of potentiating the smooth muscle contracting activity of bradykinin (BK). Chromatographic separation on Sephadex G-25 and Sephadex G-10 respectively, yielded an active peptide which at a concentration of 0.6 micrograms/ml doubled the effect of a single dose of BK on the isolated guinea-pig ileum. HPLC chromatography showed this material to contain one major and 4 minor components. The active peptide was 2-3 times more active than Captopril in the potentiation of the effects of BK on rat arterial blood pressure and on the isolated guinea pig ileum. It also showed marked capacity to inhibit angiotensin I-converting enzyme.
Assuntos
Venenos de Crotalídeos/farmacologia , Peptídeos/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicinina/farmacologia , Venenos de Crotalídeos/química , Feminino , Liofilização , Cobaias , Íleo/efeitos dos fármacos , Técnicas In Vitro , Masculino , Peso Molecular , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Peptídeos/isolamento & purificação , RatosRESUMO
Several bradykinin potentiators were identified in the venom of Bothrops jararacussu by chromatographic techniques and biological assays. One of them which was isolated inhibited the angiotensin-converting enzyme in vitro and potentiated the bradykinin-induced lowering of the arterial pressure in the rat.
