Perinatal energy stores and excessive fat deposition in genetically obese (fa/fa) rats.
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. +/fa and fa/fa hybrids were identified by molecular polymorphisms approximately 1 cM 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 litter-mates, nor did the hepatic and adipose tissue triglycerides in 24-h-old 13MBN hybrid pups. The manifest differences between fatty and lean 16-day-old pups thus do not depend on differences in perinatal energy stores.
Meierfrankenfeld
B
B
W. G. Kerckhoff-Institut, Max-Planck-Institut für Physiologische und Klinische Forschung, Bad Nauheim, Germany.
Abelenda
M
M
Jauker
H
H
Klingenspor
M
M
Kershaw
E E
EE
Chua
S C
SC
Leibel
R L
RL
Schmidt
I
I
D000273:Adipose Tissue / Q000473:pathology*; D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D001823:Body Composition; D004734:Energy Metabolism; D005260:Female; D005838:Genotype; D006003:Glycogen / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008297:Male; D015335:Molecular Probes; D008969:Molecular Sequence Data; D009765:Obesity / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D051381:Rats; D011914:Rats, Inbred BN; D011924:Rats, Zucker; D014280:Triglycerides / Q000378:metabolism
D007328:Insulin; D015335:Molecular Probes; D014280:Triglycerides; D006003:Glycogen