Effects of the root crude extract and kaurenoic acid from viguiera robusta (asteraceae) on rat carotid contractions induced by phenylephrine or KCI: a temporal study - Tirapelli, Carlos Renato; Ambrosio, S. R.; Costa, Fernando Batista da; de Oliveira, Ana Maria (Jornada Anual de Pesquisa e Pós-Graduaão do Departamento de Farmacologia FMRP-USP, 2000)