Abstract
The influence of an intensive exercise regime on cathepsin D and MMP-9 activity in hind limb muscles was investigated. We hypothesized that high-intensity exercise would increase the number of these proteins, indicating their involvement in the pathogenesis of exercise-induced muscle injury. Muscle fibers from the gastrocnemius and soleus were used from young (6-mo-old) female rats (n = 6) who completed 10 consecutive days of treadmill running at high intensity (34 m min-1gradually up to 40 min per day), compared with nonrunning, age and sex-matched rats (n = 6). After a high-intensity exercise regime, cathepsin D activity significantly increased in the gastrocnemius (from 6.6 x 10-3to 10.7 x 10-3or 61% nM tyrosine x mg protein x min-1) and the soleus (from 5.9 x 10-3to 8.9 x 10-3or 66%). The activity level of mRNA MMP-9, expressed as ng mg-1protein, increased in both muscles subjected to intensity running. The results of this study suggest that high-intensity running results in an elevation in the activity of lysosomal enzymes involved in matrix protein degradation.
Original language | English |
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Pages (from-to) | 79-86 |
Number of pages | 8 |
Journal | Journal of Basic and Clinical Physiology and Pharmacology |
Volume | 18 |
Issue number | 1 |
DOIs | |
State | Published - 2007 |
Externally published | Yes |
Keywords
- D
- MMP-9
- cathepsin
- exercise
- muscles
- rats
ASJC Scopus subject areas
- Physiology
- Pharmacology
- Drug Discovery