Calixto J B, Strobel G H, Cruz A B, Yunes R A
Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brasil.
Braz J Med Biol Res. 1988;21(5):1015-8.
The influence of an aqueous/ethanolic extract of M. velutina (CE) and of two compounds (MV 8608 and MV 8612) purified from the plant on BK-, Ad- and K+-induced responses of the rat duodenum was analyzed in vitro. In preparations precontracted with Ca2+, the CE (1 and 2 mg/ml) markedly inhibited BK-induced relaxation in a dose-dependent manner but was less effective against Ad-induced relaxation. The CE (0.5 mg/ml) also antagonized BK-induced relaxation and contraction of strips bathed in normal medium. The two compounds from M. velutina (10 and 20 micrograms/ml) also promoted a dose-dependent blockade of both responses to BK, only slightly depressing the response to K+.
