title: Antagonistic effect of yangambin on platelet-activating factor (PAF)-induced cardiovascular collapse.
abstract: The cardiovascular protective effects of yangambin, a novel and specific naturally-occurring platelet activating factor (PAF) receptor antagonist, were investigated in the pentobarbital anesthetized and artificially ventilated rat. Yangambin (3-30 mg kg(-1)) as well as the reference PAF antagonist WEB 2086 (0.1-1.0 mg kg(-1)) prevented the circulatory collapse elicited by the intravenous administration of PAF (0.5 μg kg(-1)), in a dose-dependent manner. Yangambin did not interfere with the hypotensive effect of several endogenous vasoactive mediators such as acetylcholine, bradykinin, histamine and serotonin. Moreover, when adminstered as a post-treatment the antagonist showed the ability to reverse the cardiovascular effects induced by PAF (1.0 μg kg(-1)). The protective effect of yangambin showed to have a duration of action of more than 2 hours. It is concluded that yangambin is a selective antagonist of the cardiovascular effects of PAF and therefore constitutes a potential therapeutic agent in different shock states where abnormal PAF release is supposed to play an important role.
authors.affiliation: Departamento de Fisiologia e Farmacodinámica, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: E V
authors.initials: EV
authors.lastname: Tibiriçá
authors.forename: K
authors.initials: K
authors.lastname: Mosquera
authors.forename: M
authors.initials: M
authors.lastname: Abreu
authors.forename: R
authors.initials: R
authors.lastname: Ribeiro
authors.forename: F A
authors.initials: FA
authors.lastname: Carvalho
authors.forename: J M
authors.initials: JM
authors.lastname: Barbosa-Filho
authors.forename: R S
authors.initials: RS
authors.lastname: Cordeiro