title: Reduction of spinal PGE2 concentrations prevents swim stress-induced thermal hyperalgesia.
abstract: We evaluated the association between spinal PGE2 and thermal hyperalgesia following repeated stress. Thermal nociception was determined in male Sprague-Dawley rats using the hot-plate test, before and after forced-swimming; non-conditioned rats served as controls. Animals were pretreated with ketoprofen or meloxicam, preferential COX-1 and COX-2 inhibitors, respectively. After the second hot-plate test, we measured serum corticosterone (stress marker), and lumbar spinal PGE2 (neuroinflammation marker) under peripheral inflammation (1% formalin plantar injection). Stressed rats displayed response latencies 40% shorter and inflammatory spinal PGE2 levels 95% higher than controls. Pretreatment with ketoprofen or meloxicam prevented hyperalgesia and elevation of spinal PGE2, increasing the escape behavior time during forced swimming 95% respect to saline-treated rats. Corticosterone levels in stressed rats were 97% higher than controls; COX inhibitors reduced them by 84%. PGE2 could participate in stress-induced hyperalgesia, learned helplessness, and corticosterone production, supporting the use of non-steroidal anti-inflammatory drugs (NSAIDs) for persistent pain associated with chronic stress and depression.
authors.affiliation: Section of Neuropharmacology and Neuroscience, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Faculty of Medicine, University of Zulia, Apartado Postal 23, Maracaibo 4001-A, Venezuela.
authors.forename: Coram
authors.initials: C
authors.lastname: Guevara
authors.affiliation: Section of Neuropharmacology and Neuroscience, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Faculty of Medicine, University of Zulia, Apartado Postal 23, Maracaibo 4001-A, Venezuela.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Fernandez
authors.affiliation: Section of Neuropharmacology and Neuroscience, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Faculty of Medicine, University of Zulia, Apartado Postal 23, Maracaibo 4001-A, Venezuela.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cardenas
authors.affiliation: Section of Neuropharmacology and Neuroscience, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Faculty of Medicine, University of Zulia, Apartado Postal 23, Maracaibo 4001-A, Venezuela. Electronic address: hsuarezroca@yahoo.com.
authors.forename: Heberto
authors.initials: H
authors.lastname: Suarez-Roca
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D003345:Corticosterone / Q000097:blood; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism*; D004924:Escape Reaction; D006358:Hot Temperature; D006930:Hyperalgesia / Q000209:etiology / Q000378:metabolism* / Q000523:psychology; D007660:Ketoprofen / Q000494:pharmacology; D008297:Male; D000077239:Meloxicam; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism* / Q000523:psychology; D013550:Swimming; D013843:Thiazines / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D016861:Cyclooxygenase Inhibitors; D013843:Thiazines; D013844:Thiazoles; D007660:Ketoprofen; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone; D000077239:Meloxicam; D003345:Corticosterone
keywords: Corticosterone; Cyclooxygenase; Forced-swimming; Ketoprofen; Meloxicam; Prostaglandin E(2); Thermal hyperalgesia