The Effects of Downhill Running and Maturation on Histological and Morphological Properties of Tendon and Enthesis in Mice.
Kaichi OzoneYuki MinegishiYuichiro OkaMichiaki SatoNaohiko KanemuraPublished in: Biology (2023)
To date, it remains unclear how overuse affects the tendons and entheses at different stages of maturation. Therefore, we evaluated histological and morphological changes in the tendons and entheses in adolescent (4-week-old) and adult mice (8-week-old) by performing flat-land and downhill running exercises. The mice were divided into the Sedentary, High Flat (flat-land high-speed running; concentric-contraction exercise), Low Down (downhill low-speed running; eccentric-contraction exercise), and High Down (downhill high-speed running; eccentric-contraction exercise) groups. Histological changes and inflammatory factor expressions were compared in the entheses and tendons after 4 weeks of exercise. Downhill, but not flat-land high-speed running, induced muscle-tendon complex hypertrophy in both adolescent and adult mice. Histological enthesis changes were induced in both groups during downhill running but were less pronounced in adult mice. Conversely, no significant cell aggregation or fiber orientation changes were observed in the tendon, but increased inflammatory factors were observed in both groups, with significantly higher expression in the tendons of adult mice. Downhill running induced histological and morphological enthesis changes and inflammatory factor increase in the tendons, regardless of running speed variations. These results may help elucidate the pathogenesis of enthesopathy and tendinopathy, which have different pathophysiologies despite having the same pathogenetic factors.
Keyphrases
- high intensity
- high speed
- resistance training
- high fat diet induced
- physical activity
- atomic force microscopy
- high glucose
- young adults
- randomized controlled trial
- mental health
- oxidative stress
- body composition
- skeletal muscle
- clinical trial
- stem cells
- rotator cuff
- type diabetes
- high resolution
- metabolic syndrome
- cell therapy
- adipose tissue
- mesenchymal stem cells
- long non coding rna
- binding protein
- preterm birth
- wild type
- mass spectrometry
- water quality