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Mitochondrial function in physically active older adults with sarcopenia
Author(s) -
Waters Debra L,
Qualls Clifford,
Gasparovich Charles,
Mullins Paul,
Raj Dominic
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1163.20
Subject(s) - sarcopenia , mitochondrion , medicine , endocrinology , chemistry , biochemistry
Sarcopenia is prevalent during aging and has been linked to mitochondrial dysfunction. The role of physical activity in protecting against sarcopenia and preserving mitochondrial function is debated due to its dual role of increasing muscle function while increasing free radical production. To investigate these relationships, healthy normal lean (NL: n=15) and sarcopenic (SS: n=9) subjects were recruited based on body composition (DXA, Lunar DPX TM ), age (78.5 ± 5 yr), sex, and self‐reported long‐term physical activity. Calf mitochondrial function was assessed using 4 T 31 PMRS (Bruker Biospin). Resistance was 50% of 1MVC and total work measured by force transducer. Total work was lower in SS (p<0.001) and data were scaled to total work output. At rest [Pi] was modestly elevated in SS (p=0.02). End of exercise [Pi] was lower (p=0.007) and [ADP] and pH higher (p=0.0002, p=0.05 respectively) in the SS. The [PCr] recovery rates were not different between the groups, but [ADP] during recovery remained elevated in SS (p=0.02). Elevated [ADP] during exercise can imply impaired mitochondrial function. However, the similar [PCr] recovery rates suggest an increased proton efflux in SS, that would increase pH and raise [ADP] via increased mitochondrial respiration. Our data indicate that a relationship exists between sarcopenia, long‐term physical activity, and mitochondrial function that remains to be fully elucidated. Supported by NIH/NIA R21 AG21560‐01, NCRR MO1‐RR‐00997