On betaH-Leu5-endorphin and schizophrenia

A previously unknown peptide, betaH-Leu5-endorphin, has been reported in the dialysates of schizophrenic patients. Accordingly, hemofiltrates from two schizophrenic and two control patients were examined for the presence of betaH-Leu5-endorphin. The opioid peptides were detected by a radioreceptor assay after separation and identification by gel filtration and high-performance liquid chromatography. With a detection limit of 30 pmole/L of hemofiltrate, no betaH-Leu5-endorphin or Met5-endorphin was found in controls or in patients. Whatever the possible involvement of endorphins in schizophrenic behavior, they are not present at detectable levels in the hemofiltrates of two well-characterized schizophrenic patients, thereby casting doubt on a general relationship of Leu-endorphin and schizophrenia.