Noxious stimulation decreases substance P binding in rat spinal dorsal horn

To determine the participation of NK-1 receptors in mediating inputs from noxious thermal stimulation, sustained noxious stimulation was applied to anaesthetized rats by immersing one hind paw in water for 1.5 min at different temperatures. After sacrificing the animal, lumbar spinal cords were removed and 20 microns sections were incubated with [125I]BH-substance P. Compared with unstimulated controls, binding was the least in rats given a 55 …