Antinociceptive effect of d-Lys2, Dab4N-(ureidoethyl)amide, a new cyclic 1-4 dermorphin/deltorphin analog

Systemic application of cUP-1 elicited a dose-dependent antinociceptive effect. The analgesic efficacy of cUP-1 on mechanical nociception, visceral and formalin-induced pain was comparable to that of MF. cUP-1 did not impair motor functions of mice.