Abstract
The objective of this study was to investigate the effect of a treadmill exercise protocol to prevent muscle weakness, atrophy and alterations in calcium regulation in adult, old and very old rats. Adult (7-12 months), old (29-30 months) and very old (34-36 months) F344BNF1 rats were randomly assigned to weight bearing (WB), weight bearing exercise (WBX), non-weight bearing (NWB) and non-weight bearing exercise (NWBX) groups. The WB group was considered the sedentary-control animals. NWB rats were hindlimb unweighted for 14 days. WBX and NWBX groups were exercised on a treadmill for approximately 15 min four times daily. The contractile properties [diameter, peak active force (P0), specific tension (P0/CSA)] of single myosin heavy chain type II fibers and Ca regulation [Ca2+ dependent ATPase activity] were determined. Fiber diameter reduced by 24% in the very old rats with NWB. P0 and P0/CSA declined in the young adult and very old rats with NWB. NWBX attenuated these changes in the young and very old rats. Ca2+ dependent ATPase activity increased with treadmill exercise during non-weight bearing in the young animals. In conclusion, the treadmill exercise is beneficial in attenuating the non-weight bearing-induced changes in the individual MHC type II muscle fibers of the gastrocnemius muscle.
Original language | English (US) |
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Pages (from-to) | 668-673 |
Number of pages | 6 |
Journal | Experimental Gerontology |
Volume | 43 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2008 |
Keywords
- Aging
- Calcium regulation
- F344BNF1 rats
- Gastrocnemius muscle
- Hindlimb unweighting
- MHC type II fibers
- Muscle atrophy
- Muscle weakness
- Single fiber contractile properties
- Treadmill exercise