title: D-Arg2-dermorphin tetrapeptide analogs: a potent and long-lasting analgesic activity after subcutaneous administration.
abstract: To examine pharmacological properties of D-Arg2-dermorphin tetrapeptides, six tetrapeptide analogs based on the following formulas, H-Tyr-D-Arg-Phe-Gly-OX (X = H, ethyl, n-propyl), H-Tyr-D-Arg-Phe-Sar-OX (Sar = sarcosine; X = H, methyl, ethyl), were prepared. All these analogs exhibited highly potent and long-lasting analgesia as compared with that of morphine after subcutaneous administration in mice. Among analogs tested, H-Tyr-D-Arg-Phe-Sar-OH showed the highest activities, which were 21, 30 and 58 times more active than morphine in the tail pressure, tail flick and phenylbenzoquinone writhing tests, respectively, on a molar basis.
mesh_terms: D000700:Analgesics / Q000138:chemical synthesis*; D000818:Animals; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000494:pharmacology; D018847:Opioid Peptides; D013329:Structure-Activity Relationship; D013997:Time Factors
chemical_list: D000700:Analgesics; D009842:Oligopeptides; D018847:Opioid Peptides; C030058:dermorphin