INTRACEREBROVENTRICULAR INJECTION OF PHOSPHOLIPASE A(2) INHIBITS APOMORPHINE-INDUCED LOCOMOTION IN RATS

Phospholipase A(2) (PLA(2)) is a key enzyme in phospholipid metabolism. In neurons, membrane-bound PLA(2) plays an essential role in signal transduction by affecting neurotransmitter release and receptor sensitivity. There are some reports of increased PLA(2) activity in schizophrenia. We investigated the effects of intracerebroventricular (i.c.v.) injections of PLA(2) on dopamine-mediated behavior in rats. Ten days after i.c.v. injection, PLA(2) significantly inhibited apomorphine-induced locomotion as compared with i.c.v. saline injections. The inhibition of apomorphine-induced locomotion by PLA(2) was reversible within 4 weeks after stereotaxic surgery. These findings suggest a functional inhibition of dopaminergic postsynaptic receptors by PLA(2). Accelerated phospholipid metabolism and reduced dopaminergic activity in the prefrontal cortex have been postulated to play a role in schizophrenia. Increased PLA(2) activity may be related to both abnormalities and could thus play a role in the pathophysiology of schizophrenia.