Meierfrankenfeld B, Abelenda M, Jauker H, Klingenspor M, Kershaw E E, Chua S C, Leibel R L, Schmidt I
W. G. Kerckhoff-Institut, Max-Planck-Institut für Physiologische und Klinische Forschung, Bad Nauheim, Germany.
Am J Physiol. 1996 Apr;270(4 Pt 1):E700-8. doi: 10.1152/ajpendo.1996.270.4.E700.
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.
为了确定围产期能量储备的差异对于16日龄大鼠fa/fa基因型的表型表现是否至关重要，我们研究了Zucker大鼠(13M)与挪威棕(BN)大鼠的杂交后代。通过位于距fa位点约1厘摩的分子多态性来鉴定+/fa和fa/fa杂交后代。所有幼崽的脂肪含量在出生后迅速增加，+/fa和fa/fa杂交幼崽之间的差异在7日龄和16日龄大鼠中显著，但在0、1和4日龄时不显著。对于16日龄的13MBN杂交大鼠以及13M Zucker大鼠，胴体脂肪与体重的关系图通过平行回归线紧密拟合，两个品系的fa/fa幼崽的胴体脂肪均同样高于+/fa幼崽。13MBN杂交幼崽的胎儿和新生儿血浆胰岛素浓度以及肝糖原在+/fa和fa/fa同窝幼崽之间没有差异，24小时龄的13MBN杂交幼崽的肝脏和脂肪组织甘油三酯也没有差异。因此，16日龄肥胖和瘦幼崽之间明显的差异并不取决于围产期能量储备的差异。
