Determination and clinical significance of serum kynurenine and kynurenic acid levels in schizophrenia

Abstract

Objective To investigate the clinical significance of serum kynurenine (KYN) and kynurenic acid (KYNA) determined in patients with schizophrenia(SZ)by observing the differences of serum KYN and KYNA between schizophrenia and healthy controls.Methods The serum KYN and KYNA level in schizophrenia and healthy controls were measured by high performance liquid chromatography-fluorescence (HPLC-FLD) and the content ratio of KYN to KYNA were calculated.Results The serum KYN levels had not significantly difference between schizophrenia[(2.148±0.605)μmol/L] and controls[(2.108±0.592)μmol/L]( t =0.675,P >0.05).In schizophrenia the serum KYNA [(24.231±6.831)nmol/L] was significantly decreased compare with controls [(29.420±7.595)nmol/L]( t =1.657,P <0.05), while the content ratio of KYN to KYNA (111.496±23.797) was higher than the controls(80.330±17.639) ( t =1.654,P <0.05).In paranoid schizophrenia the serum KYN was lower than it in hebephrenic schizophrenia. In paranoid schizophrenia the serum KYNA was higher than it in simple and hebephrenic schizophrenia.In hebephrenic schizophrenia the content ratio of KYN to KYNA was higher than it in paranoid and undifferentiated schizophrenia.Conclusion The serum KYNA levels and KYN/KYNA ratio in schizophrenia can be used for clinic diagnosis and therapy of schizophrenia. Key words: Schizophrenia;  Kynurenine;  Kynurenic acid;  High performance liquid chromatography