Dual modulation effects of Mas-related gene (Mrg) receptors on pain sensitivity in rats

► Mas-related gene GPCR (Mrg) are uniquely expressed in dorsal root ganglia. ► Intrathecal Mrg agonist BAM8-22 does not change pain sensitivity. ► I.t. BAM8-22 decreased tail flick latency following treatment with pertussis toxin. ► BAM8-22 decreased pain sensitivity in the presence of U73122. ► The first study to show association of Mrg receptors with Gi/o and Gq proteins in vivo.