Ramsay T G, Yan X, Morrison C
Pennington Biomedical Research Center and The Department of Animal Science, Louisiana State University, Baton Rouge 70808, USA.
J Anim Sci. 1998 Feb;76(2):484-90. doi: 10.2527/1998.762484x.
Leptin is a 16-kDa protein secreted by adipocytes that has been proposed to regulate feed intake in mice, rats, and humans. The present study was designed to characterize porcine leptin structure and expression. Successful RT-PCR resulted in development of a cDNA clone to the full length coding region of porcine leptin. Sequence data demonstrate 85% base homology to rodent, 88% to human, and a 92% homology to the bovine sequence. For assessment of porcine leptin gene expression, total RNA was extracted from the subcutaneous adipose tissue of genetically selected high backfat pigs and from contemporary crossbred swine. Total RNA derived from genetically selected high fat pigs contained 113% higher (P < .05) concentrations of porcine leptin mRNA than total RNA derived from contemporary crossbred pigs. Western blotting was used to evaluate serum levels of porcine leptin in genetically selected high backfat and contemporary, crossbred pigs. Relative levels of porcine leptin in sera from obese swine were approximately 306% higher (P < .05) than levels present in sera from contemporary, crossbred swine. These data indicate that leptin is expressed in pigs, the expressed protein is secreted into the bloodstream, and obese swine express higher levels of leptin mRNA and protein than nonobese swine at similar body weight.
瘦素是一种由脂肪细胞分泌的16千道尔顿蛋白质，有人提出它可调节小鼠、大鼠和人类的进食量。本研究旨在对猪瘦素的结构和表达进行表征。成功的逆转录聚合酶链反应（RT-PCR）产生了猪瘦素全长编码区的cDNA克隆。序列数据显示，与啮齿动物的碱基同源性为85%，与人类的为88%，与牛序列的同源性为92%。为了评估猪瘦素基因的表达，从经基因选择的高背膘猪的皮下脂肪组织和当代杂交猪中提取了总RNA。来自经基因选择的高脂肪猪的总RNA中猪瘦素mRNA的浓度比来自当代杂交猪的总RNA高113%（P < 0.05）。蛋白质免疫印迹法用于评估经基因选择的高背膘猪和当代杂交猪血清中猪瘦素的水平。肥胖猪血清中猪瘦素的相对水平比当代杂交猪血清中的水平高约306%（P < 0.05）。这些数据表明，瘦素在猪中表达，表达的蛋白质分泌到血液中，并且在相似体重下，肥胖猪比非肥胖猪表达更高水平的瘦素mRNA和蛋白质。
