Studies on concentrations of NA and HVA and activity of DBH in the serum from schizophrenic patients, first-degree relatives and normal subjects

Abstract

The serum noradrenaline (NA), homovanillic acid (HVA) and dopamine β-hydroxylase (DBH) have been examined in neuroleptic-free and -treated patients, healthy first-degree relatives of the patients and normal subjects. Analysis of variance (ANOVA) revealed significant differences in the concentrations of serum NA( F = 2.91, p < 0.05) and HVA( F = 3.58, p < 0.05), and in the activity of serum DBH( F = 2.77, p < 0.05) among the four groups. The serum NA was significantly higher in neuroleptic-free patients (475±220pg/ml, n = 18), than in healthy first-degree relatives (343±189 pg/ml, n = 37, p < 0.05) or in normal subjects (354±111 pg/ml, n = 17, p < 0.05), and it also was significantly higher in neuroleptic-treated patients (442±223 pg/ml, n = 58) than in healthy first-degree relatives ( p < 0.05) or in normal subjects ( p < 0.05). There was a trend towards high serum HVA in neuroleptic-free patients (11.3±6.3 ng/ml, n = 17) compared with the other three groups. The serum DBH activity was high in neuroleptic-free patients (31.2±15.6 nmol/ min/ml, n = 17), and significantly in comparison with those treated with neuroleptic drugs (21.6±10.9 nmol/ min/ml, n = 56, p < 0.05). There was a significant negative correlation between HVA concentration and DBH activity in the serum from neuroleptic-free patients ( r = −0.64, n = 16, p < 0.01), and there appeared to be three subgroups with alterations of serum DBH activity and HVA concentration. The concentrations of serum HVA or NA, or the activity of serum DBH did not correlate with the severity of illness. These results suggest that disturbances of metabolic pathways of catecholamines may be involved in schizophrenia and that this group of schizophrenic patients may be heterogeneous in neurochemistry.