الملخص
Abstract Administration of chlorpromazine at ( 50 mg / kg / day ) orally for a period of 21 days resulted in a significant increase in chick blood plasma and RBC acetyl cholinesterase activity by 43 % and 63% respectively , where as only a slight and non significant increase was observed when diazepam was given at ( 30 mg / kg / day ) orally in comparison with control group . However once The drugs were been discontinued, the enzyme activity returned to pretreatment level in about 11-16 days in group received chlorpromazine, suggesting that the drugs effect is reversible.