Iwasawa A, Watanabe Y, Kobayashi H, Sho K, Kondo Y, Wakabayashi K, Kamiyoshi M
Department of Animal Science and Technology, Faculty of Agriculture, Gifu University, Japan.
Poult Sci. 1998 Jan;77(1):156-62. doi: 10.1093/ps/77.1.156.
An in vitro bioassay for mammalian thyroid stimulating hormone (TSH) based on TSH-induced cyclic adenosine 3',5'-monophosphate (cAMP) production in FRTL-5 cells, a rat thyroid cell line, was used to measure chicken TSH. The addition of chicken pituitary homogenate equivalent to > or = 25% of a chicken pituitary gland to cultured FRTL-5 cells increased cAMP within these cells in a dose-dependent manner. The glycoprotein fraction derived from the pituitary homogenate was further fractionated by isoelectric focusing within a pH range of 5 to 11. Analysis of the focused fractions by the bioassay detected three major components with isoelectric points of 9.30, 7.12, and 3.82, in addition to several minor ones distributed over a wide range of pH, from alkaline to acidic. The isoelectric focusing profile obtained by the bioassay was clearly different from those obtained by radioimmunoassay for chicken LH and radioreceptor assay for chicken FSH, indicating that fractions contained chicken TSH. The homogenate of the cephalic portion of the chicken anterior pituitary gland was 4.46 times more active than that of the caudal portion in the bioassay, which is consistent with previous findings on localization of TSH in the chicken pituitary. We conclude that the bioassay using FRTL-5 rat thyroid cells is a sensitive, specific, and time-saving method of measuring chicken TSH.
基于促甲状腺激素（TSH）诱导大鼠甲状腺细胞系FRTL-5细胞产生环磷腺苷（cAMP），建立了一种体外生物测定法来检测鸡促甲状腺激素。向培养的FRTL-5细胞中添加相当于≥25%鸡垂体的鸡垂体匀浆，这些细胞内的cAMP以剂量依赖方式增加。垂体匀浆中的糖蛋白组分在pH 5至11范围内通过等电聚焦进一步分级分离。通过生物测定法分析聚焦组分，除了在从碱性到酸性的广泛pH范围内分布的几个次要组分外，还检测到三个主要组分，其等电点分别为9.30、7.12和3.82。通过生物测定法获得的等电聚焦图谱与通过鸡促黄体生成素（LH）放射免疫测定法和鸡促卵泡激素（FSH）放射受体测定法获得的图谱明显不同，表明这些组分含有鸡促甲状腺激素。在生物测定中，鸡垂体前叶头部匀浆的活性比尾部匀浆高4.46倍，这与先前关于鸡垂体中促甲状腺激素定位的研究结果一致。我们得出结论，使用FRTL-5大鼠甲状腺细胞的生物测定法是一种灵敏、特异且省时的检测鸡促甲状腺激素的方法。
