The Journal of pharmacology and experimental therapeutics
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J. Pharmacol. Exp. Ther. · Feb 1976
In vivo actions of clozapine and haloperidol on the turnover rate of acetylcholine in rat striatum.
We have measured acetylcholine (ACh) content and turnover rate (TRACh) in striatum and cortex of rats receiving haloperidol and clozapine i.p. Both clozapine (30 mumol/kg) and haloperidol (10 mumol/kg) reverse the decrease in striatal TRACh elicited by apomorphine (11 mumol/kg) while each antipsychotic affects the steady state and the TRACh in striatum differently. Haloperidol fails to change striatal ACh content but increases the TRACh; chozapine (15 and 30 mumol/kg) neither decreases the content of ACh nor changes the TRACh in striatum. ⋯ Moreover, clozapine and benztropine reverse the increase in striatal TRACh elicited by haloperidol. The increase in striatal TRACh elicited by haloperidol could be of value to explain the extrapyramidal action of this drug. The anticholinergic action of clozapine could explain the absence of extrapyramidal side effects observed with this drug.