Angiotensin (1–7) Attenuates the Nociceptive Behavior Induced by Substance P and NMDA <i>via</i> Spinal MAS1

The intrathecal (i.t.) injection of substance P (SP) and N-methyl-D-aspartate (NMDA) induce transient nociceptive response by activating neurokinin (NK) 1 NMDA receptors, respectively. We have recently reported that angiotensin (Ang) (1–7), an N-terminal fragment Ang II, could alleviate several types pain including neuropathic inflammatory spinal MAS1. Here, we investigated whether (1–7) can inhibit the SP- NMDA-induced response. induced i.t. SP or was assessed measuring duration hindlimb scratching directed toward flank, biting and/or licking hindpaw tail for 5 min. Localization MAS1 either NK1 receptors in lumbar superficial dorsal horn determined immunohistochemical observation. attenuated co-administration (0.03–3 pmol) a dose-dependent manner. inhibitory effects (3 were A779 (100 pmol), antagonist. Moreover, analysis showed co-localized with on cells horn. Taken together, via MAS1, which receptors. Thus, (1–7)/MAS1 pathway represent therapeutic target to effectively attenuate transmission caused activation