Effect of bromocriptine on some gastrointestinal smooth muscle activities in experimental animals

ABSTRACT

The action of bromocriptine [BC] was investigated on isolated smooth muscles prepared from the fundus of the rat stomach as well as the duodenum and jejunum of rabbit. BC [25-200 mug/ml] produced a dose dependent stimulant effect on the contractility of all tested preparations which could be abolished by dopaminergic antagonist on rat fundus and by ganglion blocker on the duodenum and jejunum. However, muscarinic antagonist and histaminergic blocker could not affect such response. Larger doses of BC [400, 800 mug/ml] showed an inhibitor action which could be completely blocked on isolated rat fundus by dopaminergic antagonist while combination of alpha and beta- adrenergic blockers could abolish such response on isolated duodenum and jejunum of rabbit. Involvement of dopaminergic, adrenergic and central cholinergic receptors in the production of gastrointestinal side effects of BC is more likely