RESUMO
Bromocriptine is a potent agonist at the D2 receptor. The aim of this study is to investigate the bromocriptine effect in spontaneous motor activity, using variable doses with acute and subacute administration and variable onset of measurement using albino mice. Acute intraperitoneal administration of bromocriptine using doses of 0.625, 2.5, 5, and 10mg/kg and the control group administration of 1% tween 80[n=7] were used. Spontaneous motor activity was scored after 30 and 60min of administration. Subacute administration is as follows: group1was administered 1% tween 80asa control and group2 was administered 10mg/kg bromocriptine. Spontaneous motor activity was scored using an open field test. Acute administration of bromocriptine after 30 min [0.625 and 2.5mg/kg] did not show any significant changes in spontaneous motor activity while 5 and 10mg/kg produced a significant decrease. Acute administration of bromocriptine after 60min produced a significant decrease in spontaneous motor activity, with 0.625, 2.5, 5, and 10mg/kgdoses. Subacute administration of bromocriptine significantly increased spontaneous motor activity, compared to control. It is concluded that acute administration of bromocriptine at 30 min decreased spontaneous motor activity, only with higher doses while its acute administration after 60 min decreased spontaneous motor activity, with all doses [0.625, 2.5, 5, and 10mg/kg]. As subacute administration increased spontaneous motor activity, these findings conclude that bromocriptine which produced its effect in spontaneous motor activity is time and dose dependence.