title: The Nitric oxide/CGMP/KATP pathway mediates systemic and central antinociception induced by resistance exercise in rats.
abstract: Resistance exercise (RE) is characterized to increase strength, tone, mass, and/or muscular endurance and also for produces many beneficial effects, such as blood pressure and osteoporosis reduction, diabetes mellitus control, and analgesia. However, few studies have investigated endogenous mechanisms involved in the RE-induced analgesia. Thus, the aim of this study was evaluate the role of the NO/CGMP/KATP pathway in the antinociception induced by RE. Wistar rats were submitted to acute RE in a weight-lifting model. The nociceptive threshold was measured by mechanical nociceptive test (paw-withdrawal). To investigate the involvement of the NO/CGMP/KATP pathway the following nitric oxide synthase (NOS) non-specific and specific inhibitors were used: N-nitro-l-arginine (NOArg), Aminoguanidine, N5-(1-Iminoethyl)-l-ornithine dihydrocloride (l-NIO), Nω-Propyl-l-arginine (l-NPA); guanylyl cyclase inhibitor, 1H-[1,2,4]oxidiazolo[4,3-a]quinoxalin-1-one (ODQ); and KATP channel blocker, Glybenclamide; all administered subcutaneously, intrathecally and intracerebroventricularly. Plasma and cerebrospinal fluid (CSF) nitrite levels were determined by spectrophotometry. The RE protocol produced antinociception, which was significantly reversed by NOS specific and unspecific inhibitors, guanylyl cyclase inhibitor (ODQ) and KATP channel blocker (Glybenclamide). RE was also responsible for increasing nitrite levels in both plasma and CSF. These finding suggest that the NO/CGMP/KATP pathway participates in antinociception induced by RE.
authors.affiliation: a Department of Pharmacology , Federal University of Minas Gerais , Belo Horizonte , Brazil.
authors.forename: Giovane S
authors.initials: GS
authors.lastname: Galdino
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Xavier
authors.forename: Renato
authors.initials: R
authors.lastname: Almeida
authors.forename: Grazielle
authors.initials: G
authors.lastname: Silva
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Fontes
authors.forename: Gustavo
authors.initials: G
authors.lastname: Menezes
authors.forename: Igor D
authors.initials: ID
authors.lastname: Duarte
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Perez
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D054086:KATP Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000097:blood / Q000134:cerebrospinal fluid; D019335:Nitroarginine / Q000494:pharmacology; D059225:Nociception / Q000187:drug effects / Q000502:physiology*; D009952:Ornithine / Q000031:analogs & derivatives / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D010147:Pain Measurement / Q000187:drug effects; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D006146:Guanidines; D054086:KATP Channels; D009573:Nitrites; D010069:Oxadiazoles; D011810:Quinoxalines; D019335:Nitroarginine; D009569:Nitric Oxide; C065027:N(G)-iminoethylornithine; D001120:Arginine; D009952:Ornithine; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D006152:Cyclic GMP; C004479:pimagedine; D005905:Glyburide
keywords: Resistance exercise; antinociception; nitric oxide