Measurement of tissue volume during non-steady state high intensity
muscle contraction.
Ward, Dianne S., Marc T. Hamilton, & Philip D. Watson.
Departments of Exercise Science and Physiology, University of South
Carolina
APStracts 3:0317R, 1996.
To investigate the pressures driving water into stimulated muscle,
water distribution during and following muscle stimulation was
studied in isolated cat muscles perfused by recirculating diluted
blood. 51Cr-EDTA and Evans blue-labeled albumin were used to
determine extracellular volume and plasma volume (PV) respectively.
Change in tissue volume was calculated as -PV. Interstitial volume
(IFV) was determined from the ratio of interstitial solute (51Cr-EDTA
and sodium) mass and interstitial concentration. Interstitial mass
was determined by mass balance, and interstitial concentration was
determined from solute flux and Fick's Law. One group was stimulated
at 4 Hz for 2 min., and a second was stimulated by 80 Hz trains (1
train/sec, 0.1 sec dur.). 4 Hz stimulation increased total tissue
volume by approx. 3 ml.100g-1 and decreased IFV by 1 ml.100g-1. Train
stimulation increased total tissue volume by 6 ml.100g-1 and
decreased IFV by 4. These data indicate water moves into cells faster
than the simultaneous transcapillary flow, suggesting that
intracellular osmoles provide the primary driving pressure in
stimulation-induced swelling.
Received 3 August 1995; accepted in final form 20 June 1996.
APS Manuscript Number R488-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996