EFFECT OF NEUROLEPTICS ON PHOSPHOLIPASE A(2) ACTIVITY IN THE BRAIN OFRATS

The effect of neuroleptics on phospholipase A(2) (PLA(2)) activity in rat brain plasma membranes was studied. Chlorpromazine (10 mg/kg), flu phenazine (5 mg/kg), thioridazine (5 mg/kg), trifluoperazine (5 mg/kg) , haloperidol (2 mg/kg), and sulpiride (100 mg/kg) were administered t o rats intraperitoneally as a single dose or long-term treatment (4 we eks). The PLA(2) activity was determined 24, 48, and 72 h after the la st injection of a drug. The enzyme activity was decreased after a sing le or 4-week administration of chlorpromazine, trifluoperazine, halope ridol, and sulpiride. Fluphenazine and thioridazine caused an increase of PLA(2) activity in rat brain both after a single dose and long-ter m administration. For the first time it was shown that neuroleptics ca nnot only inhibit but also increase, PLA(2) activity. Elucidation of t his fact requires further studies.