Muscle contractile activity increases fatty acid metabolism and
transport, and fat/cd36.
Bonen, Arend, David. J. Dyck, Azeddine Ibrahimi, Nada. A. Abumrad.
1Department of Kinesiology, University of Waterloo, Waterloo,
Ontario, N2L, 3G1, Canada and 2Department of Physiology and
Biophysics, State University of New York at Stony Brook, Stony Brook
NY 11749-8661
APStracts 5:0268E, 1998.
We have examined whether i) fatty acid uptake, ii) fatty acid
transporter expression and ii) fatty acid metabolism are increased
when the oxidative capacity of skeletal muscle is increased. The
oxidative capacities of red (RTA) and white (WTA) tibialis anterior
and extensor digitorum longus (EDL) muscles were increased via
chronic stimulation (10 Hz, 24h/day for 7 days). The contralateral
muscles served as controls. After 7 days of increased muscle activity
a) palmitate uptake by giant sarcolemmal vesicles was increased two
-fold (P<0.05), b) the expression of FAT/CD36 was increased, both at
the mRNA (3.2-10 fold) and protein (3.4 fold) levels, and c)
palmitate oxidation, and esterification into triacylgycerols and
phospholipids were increased 1.5, 2.7 and 1.7 fold, respectively
(P<0.05). These data show that when the oxidative capacity of
muscle is increased, there is a parallel increase in the rate of
fatty acid transport and fatty acid transporters at the sarcolemmal
membrane, which is associated with the enhanced expression of the
membrane transporter FAT/CD36.
Received 30 July 1998; accepted in final form 1 December 1998.
APS Manuscript Number E327-8.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 18 December 1998