Influence of physical training on epinephrine stimulated lipolysis
determined by microdialysis in human adipose tissue.
Stallknecht, Bente, Lene Simonsen, Jens B[umlaut]ulow, Jorgen Vinten,
and Henrik Galbo.
Department of Medical Physiology, The Panum Institute, Department
of Clinical Physiology, Bispebjerg Hospital, and The Copenhagen
Muscle Research Centre, Rigshospitalet, Denmark
APStracts 2:0135E, 1995.
Trained humans (tr) have a higher fat oxidation during submaximal
physical work than sedentary humans (sed). To investigate if this
reflects a higher adipose tissue lipolytic sensitivity to
catecholamines, we infused epinephrine (0.3 nmol x kg-1 x min-1) for
65 min in 6 athletes and 6 sedentary young men. Glycerol was measured
in arterial blood, and intercellular glycerol concentra tions in
abdominal, subcutaneous adipose tissue were measured by
microdialysis. Adipose tissue blood flow was measured by 133Xe
washout technique. From these measurements adipose tissue lipolysis
was calculated. During epinephrine infusion intercellu lar glycerol
concentrations were lower, while adipose tissue blood flow was higher
in trained compared to sedentary subjects (P < 0.05). Glycerol
output from subcutaneous tissue (tr: 604 +/- 322 nmol x 100 g-1 x
min-1 ; sed: 689 +/- 203)(mean +/- SD) as well as arterial glycerol
concentrations (tr: 129 +/- 36 NM; sed: 119 +/- 56) did not differ
between groups. It is concluded that in intact subcutaneous adipose
tissue epinephrine stimulated blood flow is enhanced whereas
lipolytic sensitivity to epinephrine is the same in trained compared
to untrained subjects.
Received 10 February 1995; accepted in final form 23 June 1995.
APS Manuscript Number E61-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 July 1995.