Adipose tissue stearoyl-coa desaturase mrna is increased by obesity
and decreased by polyunsaturated fatty acidsd by polyunsaturated
fatty acid.
Jones, Brynn H., Margaret A. Maher, William J. Banz, Michael B. Zemel,
Jay Whelan, Pamela J. Smith, and Na[diaeresis]ima
Mousta[diaeresis]id.
Physiology Program and Department of Nutrition, University of
Tennessee, Knoxville, TN 37996-1900
APStracts 3:0057E, 1996.
Stearoyl-CoA desaturase (SCD) is a key regulatory enzyme in the
synthesis of unsaturated fatty acids. While regulation of hepatic SCD
by obesity and polyunsaturated fatty acids (PUFA) has been well
-investigated, no studies have addressed whether similar regulation
occurs in adipose tissue. We addressed these questions by feeding
control (12% corn oil) and high PUFA (48% corn oil) diets to lean and
obese Zucker rats and analyzing SCD mRNA levels in adipose tissue and
liver. We report that SCD mRNA content was dramatically elevated in
adipose tissue of obese vs. lean rats on both diets and was
significantly decreased by PUFA in both genotypes. Interestingly we
demonstrate that SCD expression was directly downregulated in a dose
-dependent manner by PUFA in 3T3-L1 adipocytes. We conclude that 1.)
obese Zucker rats overexpress the SCD gene in both liver and adipose
tissue; and 2.) PUFA directly suppress SCD expression in adipocytes.
Further studies will elucidate the mechanisms responsible for
obesity- and PUFA-mediated regulation of SCD in adipose cells.
Received 28 November 1995; accepted in final form 15 February
1996.
APS Manuscript Number E561-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96