Effect of cimetidine on rat brain dopamine, norepinephrine and S-hydroxytryptamine [5-NT] levels

ABSTRACT

The effect of cimetidine on dopamine, norepinephrine and 5-HT levels in rat brain was studied. Administration of cimetidine in a single oral dose of 100 mg/kg produced a significant increase in both dopamine and 5-HT levels and a slight nonsignificant increase in norepinephrine level. Subacute administration of cimetidine in a dose of 50 mg/kg orally once daily for 7 days produced a significant increase in dopamine level and a slight nonsignificant increase in both norepinephrine and 5-HT levels. Chronic administration of cimetidine in a dose of 50 mg/kg orally once daily for 30 days resulted in a significant decrease in dopamine level and a nonsignificant decrease in both norepinephrine and 5-HT levels. The obtained results may explain many side effects observed during administration