Avaliação nociceptiva da associação entre exercício físico e fibrina rica em plaquetas em ratos Wistar submetidos ao modelo de compressão de nervo mediano

ORIGINAL ARTICLE Rev Dor. São Paulo, 2016 apr-jun;17(2):121-4 Nociceptive evaluation of the association between physical exercises and platelet-rich fibrin in Wistar rats submitted to median nerve compression Avaliação nociceptiva da associação entre exercício físico e fibrina rica em plaquetas em ratos Wistar submetidos ao modelo de compressão de nervo mediano Jhenifer Karvat1, Camila Mayumi Martin Kakihata1, Ana Luiza Peretti1, Giovanni Ribeiro Bernardino1, José Luis da Conceição Silva2, Gladson Ricardo Flor Bertolini3 DOI 10.5935/1806-0013.20160028 ABSTRACT RESUMO BACKGROUND AND OBJECTIVES: Platelet-rich fibrin is a new and promising technique to accelerate repair, with possible analgesic effects; however, there is still a gap with regard to peripheral nerve injury and the association with physical exercises. So, this study aimed at evaluating the effects of platelet-rich fibrin associated to physical exercises on nociception and edema in experimental median nerve compression model. METHODS: Thirty-six rats, all submitted to median nerve compression, were divided in six groups: G1: without additional manipulation; G2: compression and treated with platelet-rich fibrin; G3: compression and treated with free swimming; G4: compression and walking on a treadmill; G5: free swimming + platelet-rich fibrin; G6: walking on a treadmill + platelet-rich fibrin. Injury was induced by tying the median nerve with chrome plated catgut 4.0. Platelet-rich fibrin was obtained by centrifuging 1.5 mL of blood and positioning the fibrin clot directly on the compression region. Exercises were carried out during two weeks, between the 3rd and 14th postoperative days. Nociception and edema were evaluated, respectively, by flinch threshold and plethysmometer, in moments before injury and in the 3rd, 7th and 15th postoperative days. RESULTS: There have been no differences among groups, only among evaluations, showing increased nociception and edema, which has lasted or improved, respectively, over time. CONCLUSION: Platelet-rich fibrin alone or associated to physical exercises has not changed nociception and edema. Keywords: Edema, Exercise therapy, Inflammation, Pain measurement. JUSTIFICATIVA E OBJETIVOS: Fibrina rica em plaquetas é uma técnica nova e promissora na aceleração do reparo, com possíveis efeitos analgésicos, contudo, ainda há uma lacuna com relação à lesão nervosa periférica, bem como com a associação com exercícios físicos. Assim, o objetivo deste estudo foi avaliar os efeitos da fibrina rica em plaquetas associada a exercício físico sobre a nocicepção e o edema, em modelo experimental de compressão do nervo mediano. MÉTODOS: Foram utilizados 36 ratos, todos submetidos a compressão do nervo mediano e divididos em seis grupos: G1: sem manipulações adicionais; G2: compressão e tratado com fibrina rica em plaquetas; G3: compressão e tratado com natação livre; G4: compressão e exercício de caminhada em esteira; G5: natação livre + fibrina rica em plaquetas; G6: caminhada em esteira + fibrina rica em plaquetas. O modelo de lesão foi realizado com amarria do nervo mediano, com fio catgut 4.0 cromado. Para obtenção da fibrina rica em plaquetas, 1,5mL de sangue foi centrifugado e o coágulo de fibrina foi posicionado diretamente sobre a região da compressão. Os protocolos de exercício foram realizados durante 2 semanas, entre o 3º e 14º dias de pós-operatório. As avaliações nociceptivas e de edema ocorreram, respectivamente, pelo limiar de retirada de pata e pletismometria, nos momentos prévios à lesão, no 3º, 7º e 15º dias de pós-operatório. RESULTADOS: Não houve diferenças entre os grupos, apenas entre as avaliações, denotando que houve aumento da nocicepção e do edema, o qual perdurou ou foi decaindo, respectivamente, com o passar do tempo. CONCLUSÃO: O uso isolado ou associado da fibrina rica em plaquetas com exercícios físicos não produziu alterações na nocicepção e edema. Descritores: Edema, Inflamação, Mensuração da dor, Terapia por exercício. 1. Universidade Estadual do Oeste do Paraná, Departamento de Fisioterapia, Cascavel, PR, Brasil. 2. Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Ciências Farmacêuticas, Cascavel, PR, Brasil. 3. Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação de Biociências e Saúde, Cascavel, PR, Brasil. Submitted in December 17, 2015. Accepted for publication in March 30, 2016. Conflict of interests: none – Sponsoring sources: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Correspondence to: Gladson Ricardo Flor Bertolini Rua Universitária, 2069 – Jardim Universitário 85819-110 Cascavel, PR, Brasil. E-mail: © Sociedade Brasileira para o Estudo da Dor INTRODUCTION Platelets play a critical role in angiogenesis regulation because they are responsible for activation and release of cytokines and growth factors which induce cell proliferation and activation1. In addition, platelet concentrates have been used to speed tissue repair due to the high content of platelet-derived growth factor (PDGF), of transforming growth factor beta (TGF-β), of insulin growth factor (IGF) and of vascular endothelium 121 Rev Dor. São Paulo, 2016 apr-jun;17(2):121-4 Karvat J, Kakihata CM, Peretti AL, Bernardino GR, Silva JL and Bertolini GR growth factor (VEGF)2. Platelet-rich fibrin (PRF) is a new autogenous biomaterial which may induce angiogenesis, immune control and increased circulating mesenchymal cells3. It has also great potential for routine use to control postoperative (PO) pain and discomfort, being used both to repair bone tissue and soft tissue 4. In addition, PRF is easy to use and has low cost. There are however controversies about its results 5,6, because there are few evidences of its benefits4, such as, for example, in peripheral neuropathies. Most common upper extremity neuropathy is carpal tunnel syndrome (CTS). Such condition is responsible for substantial costs for society in terms of loss of productive capacity and treatment costs7. CTS is a condition affecting millions of individuals, causing chronic pain, altered sensitivity and thenar atrophy 8. First treatment option for CTS is conservative, with the use of braces, local and oral steroids, in addition to physiotherapeutic resources such as physical exercises7. There is evidence that exercise-induced analgesia is due to both increased pain threshold and increased blood endogenous opioid levels9. Since new therapies are needed to treat peripheral neuropathies, this study aimed at evaluating the effect on nociception and edema of PRF associated to physical exercise in an experimental model of median nerve compression. METHODS Experiment was made up of 36 male Wistar rats, mean weight 363.4±59,6g and aged 12±2 weeks, kept in photoperiod of 12h, 24±1 ºC, with free water and food. Animals were randomly divided in six groups, according to treatment: G1 (n=8) – submitted to nerve compression; G2 (n=8) – nerve compression + PRF; G3 (...truncated)