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Impaired ATP release during exercise in older adults: potential mechanism for impaired skeletal muscle blood flow with advancing age
Author(s) -
Kirby Brett S,
Crecelius Anne R,
Voyles Wyatt F,
Dinenno Frank A
Publication year - 2010
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.24.1_supplement.1039.12
Subject(s) - medicine , endocrinology , forearm , adenosine triphosphate , blood flow , ageing , skeletal muscle , cardiology , surgery
Aging is associated with impaired control of skeletal muscle blood flow during exercise. In young adults, circulating adenosine triphosphate (ATP) aids in the control of muscle vascular tone during exercise. We tested the hypothesis that increases in plasma [ATP] v and ATP release during forearm exercise are impaired in aging humans. We measured forearm blood flow (FBF; Doppler ultrasound) and [ATP] v , and calculated ATP release (FBF x [ATP] v ) during 5, 15, and 25% MVC rhythmic handgrip exercise in 14 young (22±1) and 12 older (63±2 yrs) adults. Deep venous blood samples were mixed in stop solution to preserve [ATP] v for plasma measurement. FBF tended to be lower during 5% MVC and was lower during 15 and 25% MVC in older adults ( P <0.05). At rest, there were no age‐group differences in [ATP] v (Y=214±16; O=183±35 nmol/L; P =0.4) or ATP release. [ATP] v increased above rest during all exercise intensities in young adults ( P <0.05); in contrast there was no significant increase in [ATP] v in older adults. ATP release increased in a graded fashion in both age groups, however this increase was blunted ~50–60% at all exercise intensities in older adults ( P <0.05 vs young). ATP release was related to FBF during exercise in both groups (r 2 =0.73). We conclude that the increase in [ATP] v and ATP release during forearm exercise is impaired in healthy older adults and relates to the observed declines in exercise hyperemia. Supported by HL‐087952