Phospholipid-sensitive calcium-dependent protein kinase: inhibition by antipsychotic drugs

Phospholipid-sensitive Ca²⁺-dependent protein kinases partially purified from the rat cerebral cortex, pig spleen, and bovine heart were shown to be inhibited, to varying degrees, by several antipsychotic drugs including trifluoperazine, chlorpromazine, fluphenazine, haloperidol, and chlorprothixene and by the local anesthetic dibucaine. None of these drugs were found to have any significant effect on cyclic AMP-dependent and cyclic GMP-dependent protein kinases. Kinetic analysis suggests that the primary effect of the drugs is mediated through a competitive inhibition of enzyme activation by interacting with phosphlipid.