Antiallodynic effects of intrathecal orexins in a XXXX model of @entity282 .

@entity1026 @entity1931 @entity22658 @entity2228 @entity1337 @entity1510 @entity158 @entity35 @entity282 @entity23908 @entity5747
@entity22658 (hypocretin 1 and 2) are the endogenous ligands of orexin receptors, a G-protein-coupled orphan receptor family containing orexin 1 (OX1) and orexin 2 (OX2) types. @entity22658 induces @entity1337 in acute and @entity158 models. We further elucidated the possible antiallodynic effect of intrathecal orexins in a @entity35 model of @entity282 . Mechanical @entity1931 was induced by incising the @entity35 hind paw and evaluated with the withdrawal threshold to von Frey filament stimulation. Intrathecal @entity22658 (0.03-1 nmol) and orexin B (0.1-3 nmol) dose dependently attenuated the incision-induced @entity1931 . @entity22658 (ED50 = 0.06 nmol) is more potent than orexin B. The effects of @entity22658 were abolished by their respective antibodies, but not by @entity1510 , and were attenuated by @entity5747 and @entity1026 , the P2X purinergic and @entity2228 receptor antagonists, respectively. @entity23908 , an OX1 receptor antagonist, at 30 nmol completely blocked the effect of @entity22658 but, even at 100 nmol, only partially antagonized the effect of orexin B. @entity22658 antibody, @entity23908 , @entity5747 , @entity1026 , or @entity1510 enhanced the incision-induced allodynic response. It is concluded that intrathecal orexins reduce incision-induced @entity1931 through OX1 receptors. @entity2228 and P2X purinergic receptors, but not opioid receptors, might be involved in the antiallodynic effects of orexins. Endogenous orexin might be released after incision injury to activate the spinal OX1 receptors as an endogenous analgesic protector.
