Cyclic analogs of Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2) with prolonged analgesic activity and potency comparable to DAMGO

VA Medical Center, New Orleans, LA.
Peptides (Impact Factor: 2.62). 02/1994; 15(8):1567-9. DOI: 10.1016/0196-9781(94)90135-X
Source: PubMed


Two cyclic analogues of the brain peptide Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2) were synthesized and tested for analgesic activity in the rat tail flick test after intracerebroventricular (ICV) injection. The analogues were about 200-fold more potent than the parent peptide. Analgesia was dose dependent, and at 1 microgram the two analogues, the mu-selective enkephalin analogue DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol), and morphine, all produced analgesia lasting between 40 and 60 min. Analgesia of longer duration was evident at higher doses of the analogues and lasted more than 6 h after 100 micrograms, the highest dose tested. The results show that peptide analogues based on the structure of the endogenously occurring Tyr-W-MIF-1 can produce potent and long-lasting effects on nociception.

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