Variability of triacylglycerol content in human skeletal muscle
biopsy samples.
Wendling, Paula S., Sandra J. Peters, George J. F. Heigenhauser, and
Lawrence L. Spriet.
Department of Human Biology and Nutritional Sciences, University of
Guelph, Guelph, Ontario N1G 2W1, and Department of Medicine, McMaster
University, Hamilton, Ontario L8S 4J9, CANADA
APStracts 3:0218A, 1996.
The varaibility of the triacylglycerol store in human skeletal muscle
(TGm) was examined using the needle biopsy technique. Thirteen
subjects had 3 biopsies sampled from the vastus lateralis muscle of
one leg both at rest and following 90 min of cycling at 65% VO2max on
one or two occasions. Visible fat and blood were removed prior to
freezing and remaining blood, connective tissue and fat were removed
from freeze-dried fiber bundles. TGm content was measured in 2
aliquots of powdered muscle from each biopsy. Within-biopsy
variability was low at 6%. Despite precautions, adipose tissue
contamination existed in many biopsies from inactive subjects. The
TGm between-biopsy coefficient of variation (CV) was 23.5 + 14.6% (X
+ SD, n = 24), using rest and exercise time points where 3 non
-contaminated biopsies existed. The between-biopsy variability at rest
(19.8 + 7.9%, n = 10) was not significantly different from exercise
(26.1 + 17.4%, n = 14). The muscle glycogen between-biopsy CV for
rest and exercise time points was 10.0 + 10.3%. The resting TGm
content was 26.3 + 4.3 mmol/kg dry muscle and the net utilization
during the 90 min of exercise was less than the between-biopsy
variability. It is concluded that the TGm store measured in repeated
biopsies of human skeletal muscle is variable with a CV of 20-26%.
Therefore, due to this high variability only changes greater than 24%
of resting TGm content may be considered meaningful.
Received 1 December 1995; accepted in final form 8 April 1996.
APS Manuscript Number A1242-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 May 96