%0 Journal Article
%T Evaluation of the cardiovascular effects of vasicine, an alkaloid isolated from the leaves of Sida cordifolia L. (Malvaceae)
%A Silveira
%A A.L.
%A Gomes
%A M.A.S.
%A Silva Filho
%A R.N.
%A Santos
%A M.R.V.
%A Medeiros
%A I.A.
%A Barbosa Filho
%A J.M.
%J Revista Brasileira de Farmacognosia
%D 2003
%I Sociedade Brasileira de Farmacognosia
%R 10.1590/S0102-695X2003000400012
%X the cardiovascular effects of vasicine, an alkaloid isolated from the leaves of sida cordifolia l., were evaluated in this work. in non-anaesthetized rats (n=6), vasicine (1, 2.5, 5 and 10 mg/kg; i.v., randomly) induced hypotension associated with an intense bradycardia. both responses were completely abolished after atropine (2mg/kg; i.v.) and attenuated after hexamethonium (20 mg/kg; i.v.). in isolated rat mesenteric artery rings, vasicine (0.03, 0.1, 0.3, 1, 3, 10, 30, 100 and 300 ¦Ìg/ml, cumulatively) induced concentration-dependent relaxation of phenylephrine-induced tone (ic50= 3.8¡À0.9 ¦Ìg/ml; n = 6). in conclusion, the results show that vasicine produce hypotension and bradycardia which appears to be due to the stimulation of cardiac muscarinic receptors (directly and/or indirectly), and by a decrease of the peripheral resistances.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0102-695X2003000400012&lng=en&nrm=iso&tlng=en