Mechanical and morphological aspects of the calcaneal tendon of mdx mice at 21 days of age.
A relationship between compromised muscles and other tissues has been demonstrated in mdx mouse, an animal model studied for understanding of Duchenne muscular dystrophy. The hypothesis is that changes in the calcaneal tendon of mdx mice occur previous to the onset of rigorous and most marked episodes of muscle degeneration, which start suddenly after 21 days of life. Thus, this study aimed to identify possible alterations in the calcaneal tendon of mdx mouse at 21 days of age. Control and mdx tendons were submitted to mechanical tensile testing, quantification of hydroxyproline, and staining with toluidine blue and picrosirius red. Hydroxyproline content was similar between mdx and control groups. The control tendon presented higher mechanical strength (load, stress, and elastic modulus) and its morphological analysis showed a larger number of round fibroblasts, nuclei with well-decondensed chromatin, and slightly metachromatic well-stained cytoplasmic material, different from that observed in mdx tendons. The results suggest that the absence of dystrophin in mdx mouse can provoke directly or indirectly alterations in the mechanical properties and morphology of the calcaneal tendon.
Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
Wilson Romero
WR
Nakagaki
Tatiana Carla
TC
Tomiosso
Edson Rosa
ER
Pimentel
José Angelo
JA
Camilli
D000818:Animals; D001696:Biomechanical Phenomena; D002111:Calcaneus / Q000033:anatomy & histology* / Q000378:metabolism; D004195:Disease Models, Animal; D006909:Hydroxyproline / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000378:metabolism; D009136:Muscular Dystrophies / Q000378:metabolism / Q000473:pathology*; D013314:Stress, Mechanical; D013710:Tendons / Q000033:anatomy & histology* / Q000378:metabolism; D013718:Tensile Strength
D006909:Hydroxyproline
mdx mice; mechanical properties; morphology; muscular dystrophy