Selective increase of alpha 1-adrenoceptors and muscarinic cholinergic receptors in rat cerebral cortex after chronic haloperidol.
The effect of chronic administration of haloperidol on alpha 1-, alpha 2-, and beta-adrenoceptors, cholinergic muscarinic, GABAA and benzodiazepine receptors in the cerebral cortex of the rat was investigated. Doses of 0.3 and 2 mg/kg of haloperidol during 7 days increased markedly the density of alpha 1-adrenoceptors without changes in affinity. The alpha 2- and beta-adrenoceptors were not modified after neuroleptic administration. The number of muscarinic receptors were also increased after haloperidol treatment (2 mg/kg/day). However, the GABAA and benzodiazepine binding sites remained unchanged. In the brainstem an increment in the alpha 1-, but not the beta-adrenoceptors was observed. The well known increase in the dopamine receptors in the striatum was confirmed. These observations demonstrate a multireceptor effect of haloperidol in the cerebral cortex.
D000818:Animals; D001933:Brain Stem / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000145:classification / Q000187:drug effects* / Q000378:metabolism; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
D011942:Receptors, Adrenergic, alpha; D011963:Receptors, GABA-A; D011976:Receptors, Muscarinic; D006220:Haloperidol