Hart I C, Blake L A, Chadwick P M, Payne G A, Simmonds A D
Biochem J. 1984 Mar 1;218(2):573-81. doi: 10.1042/bj2180573.
Bovine growth hormone (somatotropin) was extracted from anterior pituitaries and fractionated into four protein peaks (A-D) by chromatography on DEAE-Sephacel. Analysis by high-pressure liquid chromatography and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis indicated that the homogeneity of the material increased from fraction A through to D. The properties of the fractions were examined in the following manner: immunological activity (radioimmunoassays for ruminant growth hormone and prolactin); growth-promoting activity (rat tibia test); lipolytic activity (release of glycerol from rat epididymal fat in the presence of dexamethasone); diabetogenic activity (rate of glucose transport in epididymal fat of hypophysectomized rats and intravenous insulin-tolerance tests in goats). None of the fractions contained immunoreactive prolactin and all were equally lipolytic. Although fraction A contained a small quantity of immunoreactive growth hormone it had no growth-promoting or diabetogenic activities. Both fractions B and C were diabetogenic and contained high concentrations of immunoreactive growth hormone, consistent with their growth-promoting activity. Although the growth-promoting activity of fraction D was higher than that of the other three fractions, it was not diabetogenic and was only weakly immunoreactive. These results for bovine growth hormone support the contention that growth hormone, as commonly extracted, is a mixture of different molecular forms and that these different metabolic properties of the hormone might be explained in terms of this heterogeneity.
牛生长激素（促生长素）从前叶垂体中提取出来，并通过在DEAE-葡聚糖凝胶上进行色谱分离，分成四个蛋白峰（A - D）。高压液相色谱分析和十二烷基硫酸钠/聚丙烯酰胺凝胶电泳表明，从组分A到D，材料的均一性不断提高。各组分的特性通过以下方式进行检测：免疫活性（反刍动物生长激素和催乳素的放射免疫测定）；促生长活性（大鼠胫骨试验）；脂解活性（在地塞米松存在的情况下，大鼠附睾脂肪中甘油的释放）；致糖尿病活性（垂体切除大鼠附睾脂肪中葡萄糖转运速率以及山羊静脉注射胰岛素耐量试验）。所有组分均不含免疫反应性催乳素，且脂解活性相同。虽然组分A含有少量免疫反应性生长激素，但它没有促生长或致糖尿病活性。组分B和C均有致糖尿病作用，且含有高浓度的免疫反应性生长激素，这与其促生长活性一致。虽然组分D的促生长活性高于其他三个组分，但它没有致糖尿病作用，且免疫反应性较弱。这些关于牛生长激素的结果支持了以下观点：通常提取的生长激素是不同分子形式的混合物，并且该激素的这些不同代谢特性可能可以用这种异质性来解释。
