Activation of peripheral galanin receptors: differential effects on nociception
2006 (English)In: Pharmacology, Biochemistry and Behavior, ISSN 0091-3057, E-ISSN 1873-5177, Vol. 85, no 1, 273-280 p.Article in journal (Refereed) Published
Numerous reports suggest a significant role of peripheral galanin (GAL) in pain transmission; however, due to the lack of selective galanin receptor agonists and antagonists, the role of GAL receptors (GalR1-3) in pain transmission remains unclear. In this study, a new agonist, M617, that preferentially binds to GalR1, a GalR2 agonist (AR-M1896), and a GalR2 antagonist (M871) were tested in the periphery to elucidate the role of peripheral GalR1 and GalR2 in nociception. Ipsilateral, but not contralateral, hindpaw injection of M617 reduced capsaicin (CAP)-induced flinching by approximately 50%, suggesting that GalR1 activation produces anti-nociception. This anti-nociceptive effect was blocked by intraplantar injection of the non-selective GalR antagonist M35. In contrast ipsilateral, but not contralateral, intraplantar injection of GalR2 agonist AR-M1896 enhanced the CAP-induced nociception (1.7-fold). The GalR2 antagonist M871 blocked the pro-nociceptive effect of AR-M1896 in a dose-dependent manner. This antagonist had no effect on nociceptive behaviors induced by CAP alone. The data demonstrate that activation of peripheral GalR1 results in anti-nociception but activation of peripheral GalR2 produces pro-nociception. Thus, the use of these pharmacological tools may help to elucidate the contribution of GalR subtypes in nociceptive processing, identifying potential drug targets for the treatment of peripheral pain.
Place, publisher, year, edition, pages
2006. Vol. 85, no 1, 273-280 p.
Inflammatory pain, Pro-nociception, Anti-nociception, Capsaicin, Primary afferent
Biological Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:su:diva-20678PubMedID: 16996122OAI: oai:DiVA.org:su-20678DiVA: diva2:187204