Dietary lipids regulate [beta]-oxidation enzyme gene expression in
the developing rat kidney..
F., Ouali, Djouadi F., Merlet-B[acute]enichou C. and J. Bastin.
INSERM U 319, Universit[acute]e Paris 7 Denis Diderot, 2 place
Jussieu, 75251 Paris cedex 05, France
APStracts 5:0123F, 1998.
This study examines the ability of dietary lipids to regulate gene
expression of mitochondrial and peroxisomal fatty acid [beta]
-oxidation enzymes in the kidney cortex and medulla of 3-week-old
rats, and evaluates the role of glucagon, or of peroxisome
-proliferator-activated-receptor (PPAR[alpha]) in mediating [beta]
-oxidation enzyme gene regulation in the immature kidney. The long
-chain and medium-chain acylCoA dehydrogenases (LCAD, MCAD), and
acylCoA oxidase (ACO) mRNA levels were found coordinately up
-regulated in renal cortex, but not in medulla, of pups weaned on a
high-fat diet from day 16 to day 21. Further results establish that
switching pups from a low- to a high-fat diet for only one day was
sufficient to induce large increases in cortical LCAD, MCAD, and ACO
mRNA levels, and gavage experiments show that this up-regulation of
[beta]-oxidation gene expression is initiated within 6 hours
following lipid ingestion. Treatment of pups by clofibrate, a PPARa
agonist, demonstrate that PPARa can mediate regulation of cortical
[beta]-oxidation enzyme gene expression, while glucagon was found
ineffective. Thus, dietary lipids physiologically regulate gene
expression of mitochondrial and peroxisomal [beta]-oxidation enzymes
in the renal cortex of suckling pups, and this might involve
PPAR[alpha]-mediated mechanisms.
Received 11 February 1998; accepted in final form 9 July 1998.
APS Manuscript Number F28-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 30 July 1998