CLINICAL RELEVANCE OF OPIATE RECEPTOR AND OPIOID PEPTIDE RESEARCH

Numerous pharmaceutical concerns have developed enkephalin analogues for possible therapeutic uses, hoping that derivatives of such a natural substance might be non-addicting. One controlled study suggests beneficial effects in schizophrenia of an opioid-related peptide which has no opiate activity. [Des-Tyr1]-γ-endorphin comprises amino acids 62-77 of the pituitary peptide, β-lipotropin. The absence of an N-terminal tyrosine abolishes affinity for opiate receptors. On the basis of its behavioural effects in rats [des-Tyr1]-γ-endorphin was administered to chronic schizophrenics. In a double-blind placebo-controlled crossover design the peptide in daily doses of only mg dramatically alleviated schizophrenic symptoms.