Modifications of microvascular filtration capacity in human limbs by training and electrical stimulation

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

This study investigated whether an increase in microvascular surface area as a result of endurance training, which increases human skeletal muscle capillarity, would translate to greater capacity for fluid filtration compared with strength training, which does not affect capillary supply. Values for filtration capacity, Kf, derived from the slope of calf volume change, Jv, measured by venous occlusion plethysmography, against cuff pressure during a protocol of small cumulative pressure steps, were significantly higher in endurance athletes (5.78 +/- 0.88 mL min(-1) 100 mL(-1) mmHg(-1) x 10(-3), P <0.05) than controls (3.38 +/- 0.32 mL min(-1) 100 mL(-1) mmHg(-1) x 10(-3) whereas strength-trained athletes had values similar to control (4.08 +/- 0.56 mL min(-1) 100 mL(-1) mmHg(-1) x 10(-3), ns), suggesting that surface area is important. However, when sedentary subjects underwent either a 4-week unilateral dynamic plantarflexion training programme (70% peak power, 20 min day(-1), 5 days week(-1) or a calf muscle electrical stimulation programme (8 Hz, 3 x 20 min day(-1), 5 days week(-1), neither of which caused limb blood flow to alter after training nor would be expected to increase capillarity, only the stimulation group showed a significant increase in Kf (6.68 +/- 0.62 mL min(-1) 100 mL(-1) mmHg(-1) x 10(-3) post-training vs. 3.38 +/- 0.38 pre-training, P <0.05). This may be because stimulation enhances perfusion preferentially to glycolytic fibres, or maintains high levels of vascular endothelial growth factor (VEGF) or changes lymph clearance.

Details

Original languageEnglish
Pages (from-to)359-368
Number of pages10
JournalActa Physiologica Scandanavica
Volume173
Issue number4
Publication statusPublished - 1 Dec 2001

Keywords

  • training, lower leg, fluid filtration, capillarity, electrical stimulation