EFFECTS OF DOPAMINERGIC AGONISTS AND ANTAGONISTS ON CEREBELLAR GUANOSINE-3',5'-MONOPHOSPHATE (CGMP)

Apomorphine was found to cause an increase in cerebellar cGMP content. Bromocriptine, at a dose that caused stereotypies, neither elevated cGMP, nor blocked the apomorphine- induced rise in cGMP. The apomorphine-induced rise in cGMP was effectively blocked by haloperidol and some other neuroleptics, but not by sulpiride. These actions of the neuroleptics correlated with their ability to displace 3H-spiroperidol from striatal membranes, suggesting that dopamine receptor interactions were important in the cGMP changes noted. Based on the observation that haloperidol antagonized the increase induced by restraint, it is suggested that dopaminergic systems are involved in the reaction to stress. © 1978.