Aquatic Training after Joint Immobilization in Rats Promotes Adaptations in Myotendinous Junctions

Author(s)

Rocha, Lara Caetano ^[1] ; Barbosa, Gabriela Klein ^[1] ; Pimentel Neto, Jurandyr ^[1] ; Jacob, Carolina dos Santos ^[1] ; Knudsen, Andreas B. ^[2] ; Watanabe, Ii-Sei ^[3] ; Ciena, Adriano Polican ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Inst Biosci, Lab Morphol & Phys Act LAMAF, BR-13506900 Rio Claro, SP - Brazil

^[2] Bispebjerg & Frederiksberg Hosp, IOC Copenhagen Res Ctr, Dept Sports Traumatol M51, DK-1050 Copenhagen - Denmark

^[3] Univ Sao Paulo, Inst Biomed Sci 3, Dept Anat, BR-05508000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES; v. 22, n. 13 JUL 2021.
• Web of Science Citations: 0

Abstract

The myotendinous junction (MTJ) is the muscle-tendon interface and constitutes an integrated mechanical unit to force transmission. Joint immobilization promotes muscle atrophy via disuse, while physical exercise can be used as an adaptative stimulus. In this study, we aimed to investigate the components of the MTJ and their adaptations and the associated elements triggered with aquatic training after joint immobilization. Forty-four male Wistar rats were divided into sedentary (SD), aquatic training (AT), immobilization (IM), and immobilization/aquatic training (IMAT) groups. The samples were processed to measure fiber area, nuclear fractal dimension, MTJ nuclear density, identification of telocytes, sarcomeres, and MTJ perimeter length. In the AT group, the maintenance of ultrastructure and elements in the MTJ region were observed; the IM group presented muscle atrophy effects with reduced MTJ perimeter; the IMAT group demonstrated that aquatic training after joint immobilization promotes benefits in the muscle fiber area and fractal dimension, in the MTJ region shows longer sarcomeres and MTJ perimeter. We identified the presence of telocytes in the MTJ region in all experimental groups. We concluded that aquatic training is an effective rehabilitation method after joint immobilization due to reduced muscle atrophy and regeneration effects on MTJ in rats. (AU)

• FAPESP's process: 18/09199-8 - Adaptations in the myotendinous interface of wistar rats after resisted training - morphological, biochemical and functional analysis
• Grantee: Gustavo Crivelli
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/12525-1 - Plasticity at the myotendinous junction of adult rats subjected to stretching, associated with hypertrophy and swimming training: morphological, molecular and functional analyzes, with new perspectives about sarcomerogenesis
• Grantee: Adriano Polican Ciena
• Support Opportunities: Regular Research Grants