Histopathological, biomechanical, and behavioral pain findings of Achilles tendinopathy using an animal model of overuse injury

Physiological Reports

Leila Jafari¹  Pascal Vachon²  Francis Beaudry² 

[1] Département de génie mécanique, Université de Sherbrooke, Sherbrooke, Québec, Canada;Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada

关键词: Air‐puff stimulation;    Bonar score;    calcitonin gene‐related peptide;    dynorphin A;    instrumented plier;    mechanical properties;    Randall–Selitto test;    substance P;    treadmill;   

DOI  :  10.14814/phy2.12265

来源: Wiley

【 摘 要 】

Abstract

Animal models of forced running are used to study overuse tendinopathy, a common health problem for which clear evidence for effective and accessible treatments is still lacking. In these models, pain evaluation is necessary to better understand the disease, help design and evaluate therapies, and ensure humane treatment of the animals. Therefore, the main objective of this study was to evaluate pain and pathologic findings in an animal model of moderate Achilles tendinopathy induced by treadmill running. Air puffs, instead of electrical shocks, were used to stimulate running so that pain associated with stimulation would be avoided. Pressure pain sensitivity was evaluated in vivo using a new instrumented plier, whereas spinal cord peptides were analyzed ex vivo with high-performance liquid chromatography tandem mass spectrometry. Tendon histologic slides were semiquantitatively evaluated, using the Bonar score technique and biomechanical properties, using the traction test. After 8 weeks of treadmill running (2 weeks for adaptation and 6 weeks for the lesion protocol), the protocol was stopped because the air puffs became ineffective to stimulate running. We, nevertheless, observed some histologic changes characteristic of overuse tendinopathy as well as decreased mechanical properties, increased Substance P and dynorphin A peptides but without pressure pain sensitivity. These results suggest that air-puffs stimulation is sufficient to induce an early stage tendinopathy to study new therapeutic drugs without inducing unnecessary pain. They also indicate that pain-associated peptides could be related with movement evoked pain and with the sharp breakdown of the running performance.

【 授权许可】

CC BY   
© 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

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