Fernanda Madeira1, Rômulo Nolasco de Brito1, Aline A Emer1, Ana Paula Batisti1, Bruna Lenfers Turnes2, Afonso Shiguemi Inoue Salgado3, Francisco José Cidral-Filho1, Leidiane Mazzardo-Martins4, Daniel Fernandes Martins5. 1. Experimental Neuroscience Laboratory (LaNEx), Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil; Postgraduate Program in Health Sciences, Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil. 2. Experimental Neuroscience Laboratory (LaNEx), Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil; Laboratory of Bioenergetics and Oxidative Stress (LABOX), Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil. 3. Experimental Neuroscience Laboratory (LaNEx), Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil; Postgraduate Program in Health Sciences, Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil; Coordinator of Integrative Physical Therapy Residency, Centro Universitário Filadélfia, Londrina, PR, Brazil. 4. Postgraduate Program in Neuroscience, Center of Biological Sciences, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil. 5. Experimental Neuroscience Laboratory (LaNEx), Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil; Postgraduate Program in Health Sciences, Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil. Electronic address: daniel.martins4@unisul.br.
Abstract
OBJECTIVE: Warm water immersion therapy (WWIT) has been widely used in the treatment of various clinical conditions, with analgesic and anti-inflammatory effects. However, its mechanism of action has not been fully investigated. The present study analyzed the role of spinal inhibitory neuroreceptors in the antihyperalgesic effect of WWIT in an experimental model of inflammatory pain. METHODS: Mice were injected with complete Freund's adjuvant (CFA; intraplantar [i.pl.]). Paw withdrawal frequency to mechanical stimuli (von Frey test) was used to determine: (1) the effect of intrathecal (i.t.) preadministration of naloxone (a non-selective opioid receptor antagonist; 5 µg/5 µl), (2); AM281 (a selective cannabinoid receptor type 1 [CB1] antagonist; 2 µg/5 µl), (3); and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; a selective adenosine A1 receptor antagonist; 10 nmol/5 µl), on the antihyperalgesic (pain-relieving) effect of WWIT against CFA-induced hyperalgesia. RESULTS: Intrathecal naloxone, AM281, and DPCPX significantly prevented the antihyperalgesic effect of WWIT. This study suggests the involvement of spinal (central) receptors in the antihyperalgesic effect of WWIT in a model of inflammatory pain. CONCLUSIONS: Taken together, these results suggest that opioid, CB1, and A1 spinal receptors might contribute to the pain-relieving effect of WWIT.
OBJECTIVE: Warm water immersion therapy (WWIT) has been widely used in the treatment of various clinical conditions, with analgesic and anti-inflammatory effects. However, its mechanism of action has not been fully investigated. The present study analyzed the role of spinal inhibitory neuroreceptors in the antihyperalgesic effect of WWIT in an experimental model of inflammatory pain. METHODS:Mice were injected with complete Freund's adjuvant (CFA; intraplantar [i.pl.]). Paw withdrawal frequency to mechanical stimuli (von Frey test) was used to determine: (1) the effect of intrathecal (i.t.) preadministration of naloxone (a non-selective opioid receptor antagonist; 5 µg/5 µl), (2); AM281 (a selective cannabinoid receptor type 1 [CB1] antagonist; 2 µg/5 µl), (3); and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; a selective adenosine A1 receptor antagonist; 10 nmol/5 µl), on the antihyperalgesic (pain-relieving) effect of WWIT against CFA-induced hyperalgesia. RESULTS: Intrathecal naloxone, AM281, and DPCPX significantly prevented the antihyperalgesic effect of WWIT. This study suggests the involvement of spinal (central) receptors in the antihyperalgesic effect of WWIT in a model of inflammatory pain. CONCLUSIONS: Taken together, these results suggest that opioid, CB1, and A1 spinal receptors might contribute to the pain-relieving effect of WWIT.
Authors: Daniel F Martins; Aline Siteneski; Daniela D Ludtke; Daniela Dal-Secco; Adair R S Santos Journal: Mol Neurobiol Date: 2016-09-13 Impact factor: 5.590