Cholecystokinin and other neuropeptides in the cerebrospinal fluid (CSF) in psychiatric disorders

CCK function has been hypothesized to be diminished in schizophrenia. It is well-known that there are several fractions of CCK, and it is now possible to determine at least two fractions of CCK-8 in CSF. We have measured CCK-8 in CSF by the use of two antisera, Antiserum 278 and Antiserum G160, in patients with schizophrenia and depressive disorders. 47 patients with schizophrenia, endogenous and non-endogenous depression and 15 controls entered the study. CSF was obtained by lumbar puncture. The antisera used to measure CCK have the following characteristics: Antiserum 278 detects small bioactive C-terminal fragments and Antiserum G 160 binds all larger molecular forms of CCK, both with significantly higher potency than the sera previously used. Comparison of CSF-CCK level did not show significant differences between the different diagnostic groups. A significant correlation between CSF-CCK level and age was demonstrated for all patients examined for both CCK fractions. When comparing the CSF-CCK level measured by the two antisera, a significant correlation was seen. The present study indicates that even when a more specific analytical method is applied, a possible imbalance between CCK and dopamine in schizophrenia or in any of the other diagnostic groups investigated is not reflected in CSF-CCK concentrations. ? Cholecystokinin, neuropeptides, cerebrospinal fluid, psychiatry.