Orexin A and B (hypocretin 1 and 2) are novel hypothalamic peptides and two receptor subtypes, OXjR and OX2 R, were identified. Orexins are implicated in hyper-phagia, arousal, and neuroendocrine and auto-nomic regulations. Recently, orexins were found to be antinociceptive supraspinally and spinally but sympathetically stimulating. This review summarizes the analgesic effects of orexins reported in acute, inflammatory, and neuropathic pain animal models. The antinociceptive effects of orexins are mediated by OXjR, but not opioidreceptors. Purinergic P2X and glycine receptors are supported to be involved in the intrathecal orexin-induced antiallodynia. Endogenous orexins may play a protective role after nociceptive Stimulation.
|Journal||Journal of Neuropathic Pain & Symptom Palliation|
|Publication status||Published - 2011|
- orexin receptors