Skeletal muscle dysfunction is of profound clinical significance in the elderly. The focus of this application is to elucidate mechanisms underlying pathophysiologic adaptation of skeletal muscle to aging and to evaluate the effects of superimposed exercise on these adaptations.
Four specific aims are outlined: 1. To elucidate age associated alterations in the expression and activity of the Na-K ATPase. This biochemical evaluation will look at muscle group specificity, subcellular distribution, sub unit association, and pre and post translational mechanisms of modification. 2. To evaluate whether physical activity in skeletal muscle can attenuate or reverse age associated changes in the these various features of Na-K ATPase. 3. To explore whether or not aging is associated with altered potassium balance which would be reflective of altered Na-K pump function. 4. To test the hypothesis that physical activity will improve potassium balance in skeletal muscle during the process of aging. The application will make use of a variety of biochemical techniques and also microdialysis to test tissue potassium fluxes.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
1R01AG016822-01A2
Application #
6193644
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Program Officer
Mccormick, Anna M
Project Start
2001-09-01
Project End
2006-08-31
Budget Start
2001-09-01
Budget End
2002-08-31
Support Year
1
Fiscal Year
2001
Total Cost
$274,534
Indirect Cost
Name
Pennsylvania State University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Li, Jianhua; Sinoway, Lawrence I; Ng, Yuk-Chow (2006) Aging augments interstitial K+ concentrations in active muscle of rats. J Appl Physiol 100:1158-63
Zhang, Lianqin; Morris, Keith J; Ng, Yuk-Chow (2006) Fiber type-specific immunostaining of the Na+,K+-ATPase subunit isoforms in skeletal muscle: age-associated differential changes. Biochim Biophys Acta 1762:783-93
Chung, Linda; Ng, Yuk-Chow (2006) Age-related alterations in expression of apoptosis regulatory proteins and heat shock proteins in rat skeletal muscle. Biochim Biophys Acta 1762:103-9
Reis, Justin; Zhang, Lianqin; Cala, Steve et al. (2005) Expression of phospholemman and its association with Na+-K+-ATPase in skeletal muscle: effects of aging and exercise training. J Appl Physiol 99:1508-15
Ng, Yuk-Chow; Nagarajan, Murali; Jew, Korinne N et al. (2003) Exercise training differentially modifies age-associated alteration in expression of Na+-K+-ATPase subunit isoforms in rat skeletal muscles. Am J Physiol Regul Integr Comp Physiol 285:R733-40