title: Biological activity of Leu-enkephalin containing hydrophobic moieties.
abstract: A series of enkephalin analogues (Tyr-Gly-Gly-Phe-Leu-C-NH-R;R=C6,C8,C10,C12 and C14; C=CH2 groups) with increasing hydrophobic character have been tested behaviourally in the analgesic hot plate and tail flick tests. The analogues were administered intraperitoneally and were found to possess anti-nociceptive activity. The results indicate that apparently there is not a direct relationship between increasing hydrophobicity and activity of the enkephalin-alkyl-amide analogues. The enkephalin analogues were found to behave in the same way as the enkephalins in producing tolerance.
mesh_terms: D000698:Analgesia; D000818:Animals; D004743:Enkephalin, Leucine / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D006168:Guinea Pigs; D006358:Hot Temperature; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D004745:Enkephalins; D004743:Enkephalin, Leucine