Current Issues of Pharmacy and Medical Sciences

Analgesic effects of deltorphin analogues EW1 and EW2 in tail-immersion test in mice

Current Issues in Pharmacy and Medical Sciences Vol. 26, No. 4, Pages 448-452


1 Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland
2 Laboratory of Peptides, Department of Chemistry, University of Warsaw, Warsaw, Poland

DOI: 10.12923/j.2084-980X/26.4/a.22



The aim of the study was to evaluate whether EW1 and EW2, the newly synthesized analogues of deltorphin, a highly potent mu- (MOP) and delta-opioid receptors (DOP) ligand, induce antinociceptive effects in the tail-immersion test after intracerebroventricular (i.c.v.) administration. Our study indicates that these peptides, administered at the dose of 20 nmol, exert stronger or comparable antinociceptive effects as those exerted by morphine (13 nmol). A more detailed study indicated that β-funaltrexamine (β-FNA) – a MOP antagonist - very strongly and, to the lower extent than naltrindole (NTI), a DOP antagonist, inhibited the antinociceptive effects of peptides, observed in the tail-immersion test. Nor-binaltorphimine (nor-BNI), a kappa-opioid receptor (KOP) antagonist, did not influence that effect. Those data indicated an involvement of both types of opioid receptors, MOP and DOP, in the antinociceptive effects of the peptides with a dominant role of MOP.



deltorphin analogues, morphine, nociception, tail-immersion


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