Analgesic effect of intrathecal administration of orexin on neuropathic pain in rats.

Abstract

Orexin-A, a hypothalamic peptide found in the neurons of the lateral hypothalamus, has been shown to modulate pain. We examined whether orexin could alleviate heat-evoked hyperalgesia in rats caused by chronic constriction injury (CCI) of the sciatic nerve. Orexin-A, orexin-B, the vehicle, or orexin-A-antiserum was intrathecally administered to CCI rats. Paw withdrawal latency (PWL) was measured from 30 to 300 minutes after injection, which was repeated for 2 days. Orexin-A administration normalized deltaPWL (PWL in the CCI side minus PWL in the control side) and inhibited heat-evoked hyperalgesia in CCI rats, while orexin-A antiserum inhibited the normalization of heat-evoked hyperalgesia caused by orexin-A two-fold. In contrast, orexin-B had no significant effect. These results suggest that orexin-A may be applicable for treatment of neuropathic pain.

• Authors: Hidemichi Suyama, Masashi Kawamoto, Seiji Shiraishi, Syafruddin Gaus, Seiji Kajiyama, Osafumi Yuge
• Journal: In vivo (Athens, Greece) (In Vivo) 2004 Mar-Apr Vol. 18 Issue 2 Pg. 119-23 ISSN: 0258-851X [Print] Greece
• PMID: 15113038 (Publication Type: Journal Article)

Chemical References

• Analgesics
• Carrier Proteins
• Intracellular Signaling Peptides and Proteins
• Neuropeptides
• Orexins

Topics

• Analgesics (administration & dosage, therapeutic use)
• Animals
• Carrier Proteins (administration & dosage, therapeutic use)
• Disease Models, Animal
• Hot Temperature
• Hyperalgesia (drug therapy, etiology)
• Injections, Spinal
• Intracellular Signaling Peptides and Proteins
• Neuropeptides (administration & dosage, therapeutic use)
• Orexins
• Pain (drug therapy, physiopathology)
• Rats
• Sciatic Neuropathy (drug therapy, etiology, physiopathology)