Effects of epinephrine infusion on adipose tissue: interactions
between blood flow and lipid metabolism.
Samra, Jaswinder S., Elizabeth J. Simpson, Mo L. Clark, C. David
Forster, Sandy M. Humphreys, Ian A. Macdonald, and Keith N. Frayn.
Oxford Lipid Metabolism Group, Nuffield Department of Clinical
Medicine, Radcliffe Infirmary, Oxford OX2 6HE, UK, Department of
Physiology and Pharmacology, Medical School, Queen's Medical Centre,
Nottingham NG7 2UH, UK
APStracts 3:0138E, 1996.
Epinephrine has effects on both blood flow and metabolism in adipose
tissue. To investigate how these effects might interact in vivo,
epinephrine was infused into six healthy volunteers at a rate of 25
ng/kg/min. The rates of action of lipoprotein lipase and hormone
-sensitive lipase in adipose tissue were calculated by measurement of
arteriovenous differences across subcutaneous abdominal adipose
tissue, and adipose tissue blood flow was measured. Epinephrine
caused a significant rise in adipose tissue blood flow (P <
0.001), and the net efflux of non-esterified fatty acids (NEFA) from
adipose tissue increased significantly (P < 0.05). Most of this
efflux could be accounted by hormone-sensitive lipase-derived NEFA
efflux from cells (P < 0.05), but there was also a significant
rise in the contribution of lipoprotein lipase-derived NEFA (P <
0.05). We conclude that adipose tissue blood flow plays an important
role in the regulation of lipid metabolism, controlling substrate
presentation for lipoprotein lipase and also preventing the local
accumulation of fatty acids derived from both hormone-sensitive
lipase and lipoprotein lipase.
Received 2 April 1996; accepted in final form 11 July 1996.
APS Manuscript Number E162-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996