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Human skeletal muscle microvascular blood volume: effects of ageing, feeding and exercise training
Author(s) -
Phillips Bethan,
Varadhan Krishna,
Atherton Philip,
Rennie Michael,
Smith Kenneth,
Williams John
Publication year - 2012
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.26.1_supplement.1142.2
Subject(s) - postprandial , hyperaemia , medicine , skeletal muscle , perfusion , blood flow , endocrinology , ageing , blood volume , cardiology , insulin
Perfusion of the skeletal muscle microvasculature in response to hyperaemic stimuli such as feeding and exercise is crucial for whole‐body (e.g. glycaemia) and local (e.g. protein turnover) metabolic control, and in the case of exercise; performance, recovery and adaptation. Using the novel technique of contrast‐enhanced ultrasound (CEUS) we explored the effects of feeding on muscle microvascular blood volume (MBV) in 10 young (23 y, BMI; 24 kg·m 2 ) and 12 older (71 y, BMI; 26 kg·m 2 ) men, and in a sub‐group of 4 older men (73 y, BMI; 26 kg·m 2 ) after 20 wk resistance exercise training (RET). Under both postabsorptive and postprandial (IV Glamin 102 mg·kg·h −1 and 20% dextrose; blood glucose at ~7 mmol·l −1 ) conditions, femoral artery leg blood flow (LBF) was measured over 40 min, before infusion of Definity™perflutren microbubbles to assess regional quadriceps MBV by CEUS. Increases in LBF were evident only in the young men after feeding (0.51±0.02 vs. 0.57±0.04 l.min −1 , P <0.05). Similarly, increases in MBV after feeding were observed in young (+25±10%, P <0.05) but not older men (+5.3±6%; P >0.05). Intriguingly, in older men, RET faithfully restored youth‐like increases in MBV after feeding (+31±24%, P <0.05). We conclude that: (i) RET rejuvenates age‐related declines in postprandial microvascular hyperaemia and (ii) RET‐induced improvements in MBV may underlie some of the established metabolic benefits of exercise. This work was supported the Dunhill Medical Trust.