CSF-Neuropeptides in schizophrenia

Abstract

The concentrations of the neuropeptides Fraction I endorphins, neurotensin, delta-sleep inducing-peptide (DSIP) and neuropeptide Y (NPY) as well as the amine metabolites homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA) were measured in cerebrospinal fluid (CSF) from schizophrenic patients and healthy volunteers. A significant increase of receptor active Fraction I endorphins were found in the patient group compared to controls. The increased levels were correlated to low levels of HVA indicating a relationship between central nervous opioid and dopamine activity in schizophrenia. The CSF-levels of neurotensin showed a bimodal distribution with low levels in a subpopulation of the schizophrenic patients. The decreased levels showed a tendency towards normalization during neuroleptic treatment. Significantly lower concentrations of DSIP were seen in schizophrenics with no changes after treatment with neuroleptics. In contrast, the CSF-levels of NPY did not differ between patients and controls but a significant correlation was found between NPY and HVA and 5-HIAA respectively, both in schizophrenics and controls. The findings indicate abnormal synthesis, release or degradation of the neuropeptides Fraction I endorphins, neurotensin and DSIP in the central nervous system in subgroups of schizophrenic patients. Schizophrenia, CSF, homovanillic acid, delta sleep-inducing peptide (DSIP), endorphins, neurotensin.