Methionine Enkephalin: Immunomodulator in Normal Volunteers (in Vivo)

Abstract

The enkephalin, methionine enkephalin (met-enkephalin) was originally discovered to be one of the endogenous ligands for morphine receptors (Hughes et al., 1975; Simontov and Snyder, 1976). However, Plotnikoff et al., (1976) discovered anti-depressant, anti-anxiety, and anti-convulsant effects of the enkephalins, identifying a much broader spectrum of pharmacological effects than originally anticipated.