caa a22 4500 445373148 CHVBK 20180317142954.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00540-011-1240-2 doi (NATIONALLICENCE)springer-10.1007/s00540-011-1240-2 The effect of intrathecal mu, delta, kappa, and alpha-2 agonists on thermal hyperalgesia induced by mild burn on hind paw in rats [Elektronische Daten] [Hyun Kim, Tae Seol, Hee Lee, Tony Yaksh, Jong Jun] Purpose: Mild cutaneous thermal injury, leading to a first-degree burn, induces a sensation of burning pain and enhances the pain sensitivity of the skin. Opioid and α2 receptor agonists are commonly used to reduce such hyperalgesia. We investigated conditions that induced adequate thermal hyperalgesia in rats and compared the effects of μ, δ, κ, and α2 receptors at the level of the spinal cord in this model. Methods: A total of 149 male Sprague-Dawley rats were submitted to this study. A first-degree burn injury was induced in the hind paw by contact with a hot plate. The nociceptive threshold was determined by measuring the time from the application of a light beam to the hind paw to the withdrawal response (paw withdrawal latency, PWL). Various hot-plate exposure times and light beam intensities were tested to determine the conditions that induced adequate hyperalgesia. We also tested the effects of intrathecal morphine (μ agonist), DPDPE ([D-Pen2, D-Pen5] enkephalin, a δ agonist), U50488H (trans(+)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl]-benzacetamide methane sulfonate salt, a κ agonist), and ST-91 (2-[2,6-diethyl-phenylamino]-2-imidazoline, an α2 agonist) on PWL. Results: A first-degree burn was induced by contact with the hot plate for 45 s. Using current of 5.0 A, PWL was reduced by 40% from baseline. Intrathecally administered morphine, DPDPE, and ST-91, but not U50488H, showed dose-dependent antinociceptive effects in both injured and normal paws. Conclusions: Based on these findings, we could find adequate conditions for thermal hyperalgesia model. In this experimental model, μ, δ, and α2 receptor agonists produced antinociceptive effects at the level of the spinal cord, but the κ receptor agonist did not. Japanese Society of Anesthesiologists, 2011 Mu agonist nationallicence Delta agonist nationallicence Kappa agonist nationallicence Alpha-2 agonist nationallicence Thermal hyperalgesia nationallicence Intrathecal injection nationallicence Kim Hyun Department of Anesthesiology and Pain Medicine, Jeju National University College of Medicine, Jeju, Republic of Korea aut Seol Tae Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut Lee Hee Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut Yaksh Tony Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA aut Jun Jong Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut Journal of Anesthesia Springer Japan 25/6(2011-12-01), 884-891 0913-8668 25:6<884 2011 25 540 https://doi.org/10.1007/s00540-011-1240-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00540-011-1240-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kim Hyun Department of Anesthesiology and Pain Medicine, Jeju National University College of Medicine, Jeju, Republic of Korea aut NATIONALLICENCE 700 1- Seol Tae Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut NATIONALLICENCE 700 1- Lee Hee Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut NATIONALLICENCE 700 1- Yaksh Tony Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Jun Jong Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea aut NATIONALLICENCE 773 0- Journal of Anesthesia Springer Japan 25/6(2011-12-01), 884-891 0913-8668 25:6<884 2011 25 540 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer