Study Of Correlation Between Isoprene, Polyunsaturated Fatty Acids And Schizophrenia

Objectives: The purpose of this study was to investigate the correlation between schizophrenia and exhaled levels of isoprene, as well as plasma levels of the polyunsaturated fatty acids(PUFAs), linoleic acid(LA), arachidonic acid(AA), eicosapentaenoic acid(EPA) and docosahexaenoic acid (DMA). The effect of antipsychotic drugs on the levels of isoprene and PUFAs was studied. The aim of this study was to explore the role of the mevalonate pathway and the isoprenoid pathway in the pathogenesis of schizophrenia.Subjects and Methods: The subjects were inpatients with schizophrenia. The controls were patients with affective disorder and normal workers in the same psychiatric ward. Isoprene breath levels were measured by gas chromatography combined with mass spectroscopy (GC-MS). PUFAs (LA,AA,EPA and DHA) were quantitatively analyzed by gas chromatography. The schizophrenia was scored using the positive and negative symptom scale(PANSS). For the patients with schizophrenia, the same procedures were done after three weeks of therapy with antipsychotic drugs.Results: The concentrations of isoprene in the breath were significantly higher in patients with schizophrenia than in controls (P<0.05),but there were no significant differences between patients with affective disorder and normal controls (P>0.05). For the patients with schizophrenia, the concentrations of isoprene in the breath were correlated with the positive symptoms ( y = 0.705,P<0.01). After three weeks of treatment with antipsychotic drugs, the concentrations of isoprene in the breath of the patients with schizophrenia significantly decreased(P<0.05), even lower than in the breath of normalcontrols (P<0.01).The plasma concentrations of LA in untreated patients with schizophrenia, treated patients with schizophrenia, and patients with affective disorder were 818.64 ?61.22mg/L,783.75 ?52.15mg/L, and 752.96 ?57.34mg/L, respectively. All of them were significantly lower than in normal controls(995.83 25.65mg/L)(P<0.05). No significant differences in the concentrations of AA, EPA, or DHA were observed between schizophrenic patients and controls. After three weeks of treatment with antipsychotic drugs, the plasma concentrations of AA and DHA in the schizophrenic patients significantly decreased, from 153.90?3.09mg/L and 52.19?.84mg/L to 128.91+16.62 mg/Land 42.50?.01mg/L (P<0.05), respectively.Conclusions:1. The concentrations of isoprene in the breath were significantly higher in patients with schizophrenia than in patients with affective disorder and in normal controls. The higher concentrations were positive correlated with the positive symptoms of schizophrenia, and could be inhibited by antipsychotic drugs.2. The concentrations of LA in the plasma of untreated and treated patients with schizophrenia, and patients with affective disorder were significantly lower than in normal controls, which indicates that the deficit of LA may contribute to schizophrenia.3. Antipsychotic drugs can decrease the concentrations of AA and DHA in the plasma of patients with schizophrenia, which may be due to the inhibition of PUFA catabolism.