Specific regional differences of in vitro β-endorphin metabolism in schizophrenics

Incubation of β-endorphin (β-E; 25μM) with twice-washed brain membrane homogenates leads to the formation of several biologically active peptide fragments which have been shown to be present in the brain. Based on clinical studies, some of these endorphin fragments have been shown to be active in patients with neuropsychiatric disease states. We studied the regional specificity of β-E metabolism in frontal cortex versus putamen from sex and age matched controls versus subjects with a diagnosis of schizophrenia. The present study demonstrates that cortical tissue has a lower rate of γ-endorphin production from β-E and a similar rate of des-tyrosine-γ-endorphin production. Significant differences were noted in the production of other active fragments (β-E (1-16, 2-16, 6-21)). These results support the hypothesis that there is a regional specificity of β-E metabolism in the brain, and these differences may have important functional consequences to secreted peptides and important clinical consequences in schizophrenia.