Verapamil: a calcium channel blocker and its effect on brain monoamines in the rat

ABSTRACT

The present work is an attempt to investigate the effect of verapamil, a calcium channel blocker, on brain 5 hydroxytryptamine [5 HT], dopamine [DA] and noradrenaline [NA]. Results showed that the intraperitoneal [i.p.] injection of verapamil in doses of 1, 5, 25 and 50 mug/kg, one hour prior to sacrifice, significantly increased brain 5 HT level. A significant decrease in brain DA was detected with doses of 5, 25 and 50 mug/kg of verapamil, while 1 mug/kg caused no significant change in this parameter. Brain NA level, however, was not significantly changed with all the doses of verapamil previously mentioned when measured one hour from the injection of the drug. The mechanism of action of verapamil in the management of affective disorders and the possibility of the involvement of brain 5 HT and DA was discussed