Abstract
The effects of exercise training on the nitric oxide synthase (NOS) isoform profile in aging fast-twitch (white gastrocnemius [WG]) and slow-twitch (soleus [SOL]) muscle have not been investigated. Six-month and 27-month male Fischer-344 rats were divided into the following groups: young sedentary (YS), young treadmill exercise trained for 12 weeks, old sedentary (OS), and old exercise trained (OE). Inducible NOS (iNOS) protein expression and activity were signifi-cantly higher in OS compared with YS, whereas exercise training significantly reduced iNOS protein and activity levels in the WG. Neuronal NOS protein expression decreased with aging in WG but was upregulated significantly with exercise training in OE for both WG and SOL. Endothelial NOS (eNOS) protein levels were depressed in WG of old rats but were higher in OE than in OS. eNOS was unaffected by aging or exercise in the SOL. Our results indicate that endurance exercise training attenuates age-induced alterations of NOS isoforms with a greater response in fast-twitch compared with slow-twitch muscle.
| Original language | English |
|---|---|
| Pages (from-to) | 540-549 |
| Number of pages | 10 |
| Journal | Journals of Gerontology - Series A Biological Sciences and Medical Sciences |
| Volume | 64 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2009 |
| Externally published | Yes |
Bibliographical note
Funding Information:This study was supported by the American College of Sports Medicine , Glenn/American Federation for Aging Research , the American Heart Association Texas Affiliate ( GIA 0555064Y ), NIH ( AR054084 ), and the Korea Science and Engineering Foundation ( KOSEF-R01-2007-000-20546-0 ).
Keywords
- Aging
- Exercise
- Nitric oxide synthase
- Skeletal muscle
- eNOS
- iNOS
- nNOS