Alterations of lipolysis and lipoprotein lipase in chronically
nicotine-treated rats.
Sztalryd, Carole, Jock Hamilton, Barbara A. Horwitz, Patricia Johnson,
and Fredric B. Kraemer.
Division of Endocrinology, Gerontology, and Metabolism, Department
of Medicine, Stanford University School of Medicine, Stanford, CA
94305 and Department of Veterans Affairs Medical Center, Palo Alto,
CA 94304; Department of Neurobiology, Physiology, and Behavior, and
Department of Nutrition, University of California, Davis, Davis CA
95616-8519.
APStracts 2:0190E, 1995.
These studies examined the cellular mechanisms for lower adiposity
seen with nicotine ingestion. Rats were infused with nicotine or
saline for 1 wk and adipocytes isolated from epididymal fat pads.
Nicotine-infused rats gained 37% less weight and had 21% smaller fat
pads. Basal lipolysis was 78% higher, while the maximal lipolytic
response to isoproterenol was blunted in adipocytes from nicotine
-infused rats. The antilipolytic actions of adenosine and the levels
of serum catecholamines were unaffected by nicotine. The nicotine
-induced alteration in lipolysis was not associated with any changes
in hormone-sensitive lipase. Nicotine caused a 30% decrease in
lipoprotein lipase (LPL) activity, without any changes in LPL mass or
mRNA levels, in epididymal fat in the fed state. In contrast, LPL
activity, mass and mRNA levels in heart were increased by nicotine
whether animals were fed or fasted. These studies provide evidence
for multiple mechanistic events underlying nicotine-induced
alterations in weight and suggest that nicotine diverts fat storage
away from adipose tissue and towards utilization by muscle.
Received 19 May 1995; accepted in final form 14 August 1995.
APS Manuscript Number E227-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.