Mildner A M, Clarke S D
Unit of Performance Enhancement, Upjohn Company, Kalamazoo, MI 49001.
J Nutr. 1991 Jun;121(6):900-7. doi: 10.1093/jn/121.6.900.
A cDNA for porcine fatty acid synthase was isolated and used to examine the tissue distribution of fatty acid synthase mRNA within the pig and to determine the impact of recombinant porcine somatotropin (rpSt) and the level of dietary protein on fatty acid synthase mRNA abundance in pig liver and adipose tissue. A 1.5-kb cDNA representing the thioesterase domain of porcine fatty acid synthase was isolated from a lambda gt 11 liver cDNA library. Northern analysis with total RNA extracted from adipose tissue, liver, heart, lung, kidney and intestine revealed a single major fatty acid synthase mRNA species of 8-9 kb. The amount of fatty acid synthase mRNA in hepatic tissue was 25% of the amount in adipose tissue, which suggests that the liver may be a significant site of fatty acid synthesis in the pig. Fatty acid synthase mRNA abundance was significantly reduced in the adipose tissue (P less than 0.01) and the liver (P less than 0.1) by chronic daily administration (60 micrograms/kg) of rpSt. In addition, increasing the amount of dietary protein decreased (P less than 0.1) the abundance of fatty acid synthase mRNA in adipose tissue but had no effect on liver fatty acid synthase expression. In contrast, the abundance of adipose fatty acid binding protein mRNA was unaffected by rpSt or dietary protein. These data indicate that the reduction in the level of fatty acid synthase mRNA is a factor in the pSt-mediated suppression of fatty acid synthesis in porcine adipose tissue.
分离出猪脂肪酸合酶的互补脱氧核糖核酸（cDNA），用于检测猪体内脂肪酸合酶信使核糖核酸（mRNA）的组织分布，并确定重组猪生长激素（rpSt）和日粮蛋白质水平对猪肝和脂肪组织中脂肪酸合酶mRNA丰度的影响。从λgt 11肝脏cDNA文库中分离出一个代表猪脂肪酸合酶硫酯酶结构域的1.5千碱基对（kb）的cDNA。用从脂肪组织、肝脏、心脏、肺、肾脏和肠道提取的总RNA进行的Northern分析显示，有一个单一的主要脂肪酸合酶mRNA种类，大小为8 - 9 kb。肝组织中脂肪酸合酶mRNA的量是脂肪组织中量的25%，这表明肝脏可能是猪体内脂肪酸合成的一个重要部位。通过每天慢性给予（60微克/千克）rpSt，脂肪组织（P小于0.01）和肝脏（P小于0.1）中脂肪酸合酶mRNA的丰度显著降低。此外，增加日粮蛋白质的量会降低（P小于0.1）脂肪组织中脂肪酸合酶mRNA的丰度，但对肝脏脂肪酸合酶的表达没有影响。相比之下，脂肪脂肪酸结合蛋白mRNA的丰度不受rpSt或日粮蛋白质的影响。这些数据表明，脂肪酸合酶mRNA水平的降低是pSt介导的猪脂肪组织中脂肪酸合成抑制的一个因素。
