Schifter S
Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Copenhagen, Denmark.
Clin Chim Acta. 1993 Apr 16;215(1):99-109. doi: 10.1016/0009-8981(93)90253-z.
A highly sensitive and specific radioimmunoassay (RIA) for human calcitonin-like immunoreactivity (CT-LI) has been developed. The assay is performed directly without extraction and may be used for measurements in plasma or serum as well as buffer solutions. The detection limit of the assay is < 0.4 pmol/l, intra- and interassay variations 5 and 10%, respectively when calculated from a control sample within the range of normal concentrations. The recovery of calcitonin (CT) varied between 87 and 118% in the concentration range 10-130 pmol/l. Measurements of CT-LI in sera from 70 normal individuals, showed significantly lower concentrations in women as compared to men, 7.4 pmol/l +/- 2.1 pmol/l and 9.1 pmol/l +/- 2.2 pmol/l, respectively (mean +/- S.D.), P < 0.005. The chromatographic profile of immunoreactive CT in normal serum was investigated by gel chromatography and high pressure liquid chromatography (HPLC) and showed heterogeneity of circulating CT-LI, but with the majority eluting corresponding to the elution position of synthetic human CT. The study of physiological variations in CT levels has so far been hindered by the limitations in assay sensitivity. It is hoped that the significantly improved sensitivity of the presently described assay may contribute towards the elucidation of the physiological functions of CT.
已开发出一种用于检测人降钙素样免疫反应性（CT-LI）的高灵敏度和特异性放射免疫测定法（RIA）。该测定法无需提取即可直接进行，可用于血浆、血清以及缓冲溶液的检测。该测定法的检测限<0.4 pmol/l，根据正常浓度范围内的对照样品计算，批内和批间变异系数分别为5%和10%。在10 - 130 pmol/l的浓度范围内，降钙素（CT）的回收率在87%至118%之间。对70名正常个体血清中CT-LI的检测显示，女性的浓度显著低于男性，分别为7.4 pmol/l±2.1 pmol/l和9.1 pmol/l±2.2 pmol/l（均值±标准差），P<0.005。通过凝胶色谱法和高压液相色谱法（HPLC）研究了正常血清中免疫反应性CT的色谱图，结果显示循环CT-LI具有异质性，但大多数洗脱峰对应于合成人CT的洗脱位置。迄今为止，由于检测灵敏度的限制，CT水平生理变异的研究受到了阻碍。希望目前所述测定法显著提高的灵敏度可能有助于阐明CT的生理功能。
