Comparative study on analgesic effect of Met5-enkephalin and related lipotropin fragments.

摘要: HUGHES et al.1 have reported the isolation and structure of two pentapeptides from porcine brain with opiate agonist activity in isolated systems. The one these peptides, Met5-enkephalin, is identical sequence pituitary β-lipotropin (β-LPH) between residues 61–65 (refs 2–4). To prove biological correlation enkephalin β-LPH, a series lipotropin fragments, LPH-(61–69)-5, LPH-(61–76)-6 LPH-(61–91)-peptides7–10, been shown to vitro. Only few controversial data available so far on analgesic effect vivo above or similar fragments. Enkephalins recently induce analgesia vivo11,12. Our preliminary data5,13, however, seemed contradict observations, rather suggesting that some larger fragment(s) β-LPH may properties. We therefore compared effects Met5-enkephalin fragments containing complete at their NH2-terminus. results show function length peptide chain, being least LPH-(61–91)-peptide most potent. During preparation this paper we become aware recent observation Bradbury coworkers10,14 strong LPH-(61–91)-peptide.