NEUROLEPTIC EFFECTS ON SERINE AND GLYCINE METABOLISM

The concentrations of serine and glycine and the activity of serine hy droxymethyltransferase (SHMT) are abnormal in plasma and brains of sch izophrenics. To further elucidate the possible role of neuroleptics on the metabolism of serine and glycine and the activity of SHMT, we stu died the plasma of controls and schizophrenics on and off medications, the brains of rats treated with haloperidol, and the activity of puri fied SHMT in the presence or absence of haloperidol and fluphenazine. Plasmas of neuroleptic-treated schizophrenics had nonsignificantly low er concentrations of serine and glycine. Brains of haloperidol-treated rats had significantly lower concentrations of serine and glycine. At therapeutic levels haloperidol and fluphenazine did not inhibit the a ctivity of purified SHMT. The serine-glycine lowering effects of halop eridol and neuroleptics are discussed in the context of a possible neu roprotective potential of neuroleptics in schizophrenia.