in this study, the possible involvement of l-type voltage-operated calcium channels in the vasorelaxant effect of the flavonoid quercetin was investigated, using the isolated aortic rings from normal male rats. addition of quercetin (0.1 µm-1 mm) caused a significant dose-dependent relaxation of noradrenaline (na)- and kcl-preconstricted rings and nifedipine attenuated this response, especially...