Perinatal energy stores and excessive fat deposition in genetically
obese (fa/fa) rats.
Meierfrankenfeld, Birgit, Maria Abelenda, Heike Jauker, Martin
Klingenspor, Erin E. Kershaw, Streamson C. Chua, Jr., Rudolph L.
Leibel, and Ingrid Schmidt.
W.G. Kerckhoff-Institut, Max-Planck-Institut, f[umlaut]ur
physiologische und klinische Forschung, Parkstr. 1, D-61231 Bad
Nauheim, FRG, Universidad Complutense, Facultad de Ciencias
Biologicas, Department Biologia Animal II, E-28040 Madrid, Spain, FB
Biologie der Universit[umlaut]at Marburg, D-35032 Marburg, FRG, 4
Rockefeller University, New York, Laboratory of Human Behavior and
Metabolism, 1230 York Avenue, New York, NY, 10021-6399, USA
APStracts 2:0254E, 1995.
To find out whether perinatal differences in energy stores are
essential for the phenotypic manifestation of the fa/fa genotype in
16-day-old rats, we investigated Zucker rats (13M) X Brown Norway
(BN) hybrids. We determined gene dosage by using molecular
polyporphisms about 1cM from the fa locus. The fat content of all
pups increased rapidly after birth, and differences between +/fa and
fa/fa hybrid pups were significant in 7- and 16-day-old rats but not
at 0, 1, and 4 days of age. For 16-day-old 13MBN hybrids as well as
13M Zucker rats, plots of carcass fat vs. body mass were closely
fitted by parallel regression lines with carcass fat similarily
higher in fa/fa than +/fa pups of both strains. Fetal and neonatal
plasma insulin concentration and hepatic glycogen in the 13MBN-hybrid
pups did not differ between +/fa and fa/fa littermates. Nor did the
hepatic and adipose tissue triglycerides in 24-h-old 13MBN-hybrid
pups. Differences in perinatal energy stores are thus not essential
to the obvious manifestation of differences between 16-day-old fatty
and lean pups.
Received 16 August 1995; accepted in final form 13 October 1995.
APS Manuscript Number E393-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95