The neurokinin-1 receptor antagonist, sendide, exhibits antinociceptive activity in the formalin test

Abstract
He mouse paw formalin test. Intrathecal administration of sendide (in pmol) reduced both the early and late phases of the formalin-induced licking response. [D-Trp7]sendide also produced a significant antinociceptive response with less potent activity than sendide. Even highest doses (4000 pmol sendide and 8000 pmol [D-Trp7]sendide) examined, there was no motor paralysis of the hindlimbs. Intrathecal morphine inhibited both the early and late phases of the formalin-induced licking response in a dose-dependent manner. The results indicate that the antinociceptive effects of sendide and [D-Trp7]sendide may be mediated at NK1 receptors in the formalin-induced nociception. ∗Corresponding author: Dr. Tsukasa Sakurada, Department of Pharmacology, Tohoku College of Pharmacy, 4-4-1 Komatsushima, Sendai 981, Japan. Tel: (022) 234-4181; FAX: (022) 275-2013. (Received 2 March 1994; revision received 28 April 1994; accepted 4 May 1994.) © Lippincott-Raven Publishers....