Effects of α1- and α2-adrenoreceptor antagonists on cold allodynia in a rat tail model of neuropathic pain

Systemic administrations (0.1, 0.5, and 2 mg/kg) of α1-adrenoreceptor (AR) antagonist prazosin dose-dependently attenuated cold allodynia in a rat tail model of neuropathic pain, whereas α2-AR antagonist yohimbine exacerbated it. These results suggest that the functions of α1- and α2-AR in this model are excitatory and inhibitory, respectively, consistent with their general properties. It is also proposed that cold allodynia can be reversed by α1-AR antagonist and exacerbated by α2-AR antagonist.