Fukushima M, Nakai Y, Tsukada T, Usui T, Nakaishi S, Naito Y, Tominaga T, Senoo K, Fukata J, Ikeda H
Department of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.
Int J Obes Relat Metab Disord. 1993 Jun;17(6):337-41.
We have studied pro-opiomelanocortin (POMC) gene expression by quantifying the POMC mRNA contents in anterior pituitaries of female Wistar fatty rats, a strain obtained by transfer of the fa gene in Zucker rat to Wistar Kyoto rat, in an attempt to understand the role of ACTH synthesis in altered ACTH and corticosterone secretion in these rats. Five- and 12-week-old female Wistar fatty rats and their lean littermates were examined. Plasma ACTH levels were significantly higher in fatty rats than in lean rats (5 weeks: 114.5 +/- 17.5 pg/ml vs. 54.3 +/- 12.4 pg/ml; 12 weeks: 83.8 +/- 12.3 pg/ml vs. 51.7 +/- 6.8 pg/ml; P < 0.01). There was no significant difference between 5-week-old fatty rats and lean rats in POMC mRNA contents nor in POMC/beta-actin ratios in anterior pituitaries. Twelve-week-old fatty rats, however, had significantly higher POMC mRNA contents and also higher POMC/beta-actin ratios in anterior pituitaries than those in lean littermates (P < 0.01, approximately three-fold difference between lean and obese rats). These data suggest that the difference in POMC mRNA contents between lean and obese rats becomes apparent as they grow and develop obesity and the elevated POMC mRNA levels are at least partly responsible for the increased ACTH secretion in 12-week-old fatty rats.
我们通过定量测定雌性Wistar肥胖大鼠垂体前叶中阿片促黑激素皮质素原（POMC）mRNA的含量，来研究POMC基因的表达情况。Wistar肥胖大鼠是通过将Zucker大鼠的fa基因转移到Wistar Kyoto大鼠中获得的一个品系，目的是了解促肾上腺皮质激素（ACTH）合成在这些大鼠ACTH和皮质酮分泌改变中所起的作用。对5周龄和12周龄的雌性Wistar肥胖大鼠及其瘦的同窝仔鼠进行了检测。肥胖大鼠的血浆ACTH水平显著高于瘦大鼠（5周龄：114.5±17.5 pg/ml对54.3±12.4 pg/ml；12周龄：83.8±12.3 pg/ml对51.7±6.8 pg/ml；P<0.01）。5周龄肥胖大鼠和瘦大鼠垂体前叶中的POMC mRNA含量以及POMC/β-肌动蛋白比值均无显著差异。然而，12周龄肥胖大鼠垂体前叶中的POMC mRNA含量显著高于其瘦的同窝仔鼠，POMC/β-肌动蛋白比值也更高（P<0.01，瘦鼠和肥胖大鼠之间相差约3倍）。这些数据表明，随着瘦大鼠和肥胖大鼠的生长以及肥胖的发展，它们之间POMC mRNA含量的差异变得明显，并且POMC mRNA水平的升高至少部分导致了12周龄肥胖大鼠ACTH分泌的增加。
