[A study of the leucine enkephalin like substance and enkephalin degrading enzyme activity in human cerebrospinal fluid]

Leucine enkephalin like substance (Leu-Enk) and enkephalin degrading enzyme activity (EDEA) in cerebrospinal fluid (CSF) of three patients suffering from pain were measured. As compared with control values before treatments, the values of Leu-Enk in CSF decreased, and those of EDEA increased in all the patients. After the treatment, two patients were fortunately cured of pain, and their two values returned to normal. But the other patient could not recover from severe pain, and their values remained abnormal. It is concluded that Leu-Enk and enkephalin degrading enzyme in CSF may play an important role in regulation of pain sensitivity.