Inhibitory effects of Musanga cecropioides on noradrenaline and potassium-induced contractions in rat thoracic aorta

Abstract

The pharmacological effects of Musanga cecropioides on rat thoracic aorta were examined in high K,SUP>+ medium (55mM), Ca²⁺ 3mM) induced vasoconstriction was inhibited by Musanga cecropioides in a concentration-dependent manner. The tonic contra ctions elicited by KCI 55mM were relaxed by Musanga and were more marked in 0.45mM Ca²⁺ than 1.8mM Ca²⁺ medium. NA -induced responses were antagonized non competitively by Musanga. NA- sustained contraction was relaxed, the relaxing effect of Musanga was not antagonized by indomethacin or methylene blue. It is concluded that Musanga relaxation of the rat aorta does not involve cyclo-oxygenase, nor cAMP pathway, but unique, unlike those of known classical vasodilators.

African Journal of Biomedical Research Vol. 8(1) 2005: 59-61