향정신성 약물의 Phospholipase C와 Protein Kinase C 효소활성에 미치는 영향 - 항정신병 약물을 중심으로 一

Effects of Psychotropic Drugs on Phospholipase C and Protein Kinase C in Vitro — With Emphasis on Antipsychotic Drugs —

The effects of various psychotropic drugs on phospholipase C (PLC ) and protein kinase C (PK C ) were studied in vitro. Trifluoperazine (TFP) and chlorprom azine (CPZ) strongly inhibited activities of both PLC and PKC. Fifty percent inhibition concentration(I50) of TFP was 180jiM for PLC and 270(iM for PKC. I50S of C PZ for PLC and PKC were 270(iM and 150|iM, respectively. Haloperidol inhibited PLC activity(I50, 490(iM), but did not inhibit PKC s. Diazepam inhibit PKC weakly(I50，2mM), but did not PLC. Sulpiride did not have any effects on both PLC and PKC. TFP inhibited PLC by competitive m anner with phosphatidylinositol (Ki，20|iM). The inhibition of PKC by TFP was o f noncompetitive type to calcium(Ki, 45(jM). These results suggest that the antipsychotic drugs could be classified by their effects on PLC and PKC.