10.7910/DVN/CYOOXJ Dong-ho Youn https://orcid.org/0000-0003-2460-4610 Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea Jiyeon Jun https://orcid.org/0000-0002-4238-2751 Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea Tae Wan Kim Tae Wan Kim https://orcid.org/0000-0002-7943-4682 Department of Physiology, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea Kibeom Park https://orcid.org/0000-0002-1432-8301 Department of Anesthesiology and Pain Medicine, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Korea Harvard Dataverse 2022 Medicine, Health and Life Sciences Analgesics, Opioid Dynorphins Enkephalin, Ala(2)-MePhe(4)-Gly(5)- Hyperalgesia Orexins Orexin Receptors Pain Spinal Cord Dorsal Horn Kibeom Park Department of Anesthesiology and Pain Medicine, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Korea 2022-09-20 2022-09-20 14382 13844 571973 20309 application/vnd.openxmlformats-officedocument.spreadsheetml.sheet application/vnd.openxmlformats-officedocument.spreadsheetml.sheet application/vnd.openxmlformats-officedocument.spreadsheetml.sheet application/vnd.openxmlformats-officedocument.spreadsheetml.sheet 1.0 Creative Commons CC0 1.0 Universal Public Domain Dedication. Repeated administration of opioid analgesics for pain treatment can produce paradoxical hyperalgesia via peripheral and/or central mechanisms. Thus, this study investigated whether spinally (centrally) administered orexin A attenuates opioid-induced hyperalgesia (OIH). [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO), a selective μ-opioid receptor agonist, was used to induce mechanical hypersensitivity and was administered intradermally (4 times, 1-hour intervals) on the rat hind paw dorsum. To determine whether post- or pretreatments with spinal orexin A, dynorphin A, and antidynorphin A were effective in OIH, the drugs were injected through an intrathecal catheter whose tip was positioned dorsally at the L3 segment of the spinal cord (5 μg for all). Mechanical hypersensitivity was assessed using von Frey monofilaments. KJP-22-174