Estimates of circulating monomeric calcitonin: physiological studies in normal and thyroidectomized man.
Estimates of circulating monomeric calcitonin: physiological studies in normal and thyroidectomized man.
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循环单体降钙素的估计：正常和甲状腺切除男性的生理研究。
DOI：
10.1210/jcem-57-5-897
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
H. Heath
中科院分区：
文献类型：
--
作者：
J. Body;H. Heath
为了避免目前人降钙素 (hCT) 测定的局限性，我们开发了一种血浆 hCT 的二氧化硅提取和浓缩方法，该方法将测定的检测限降低了 40 倍（至 0.5-1.0 pg/ml），并显着提高了 CT 单体 (hCT-M) 测定的特异性。添加到 20 ml 血浆中的放射性碘标记和未标记的合成 hCT-M 的提取回收率分别为 90 +/- 1% 和 99 +/- 4%（平均值 +/- SE）。对甲状腺髓样癌患者血浆进行的凝胶过滤色谱分析表明，提取物中 hCT-M 含量显着富集。在 60 名正常个体中测量拔牙前 (iCT) 和拔牙后 (exCT) 的基础血浆免疫反应性 hCT；年轻男性的基础 exCT 水平高于年轻女性 [8.0 +/- 0.8 (+/- SE) vs. 4.6 +/- 0.5 pg/ml； P 小于 0.001]，老年男性高于老年女性（9.4 +/- 0.8 vs. 4.7 +/- 0.6 pg/ml；P 小于 0.05），但随年龄变化没有差异。 36 名受试者的钙输注（2 mg Ca/kg，持续 5 分钟）显示，男性的 exCT 分泌能力显着高于女性，但 exCT 反应并没有随着年龄的增长而下降。基础iCT和exCT浓度之间没有相关性，但Ca刺激的iCT峰值和Ca刺激的exCT峰值水平之间存在良好的相关性（r = 0.94；P小于0.001），表明hCT-M是急性刺激释放的主要形式。 6 名甲状腺完全切除个体的平均可提取 CT 水平为 2.7 +/- 0.3 pg/ml，并且在 Ca 激发后没有增加。我们发现 5 名女性在 1 个月经周期的 3 个不同场合测量的基础或 Ca 刺激的 exCT 水平没有显着差异。餐后，女性的 exCT 水平没有变化，但男性的 exCT 水平持续增加（3 小时时比基线高 28 +/- 7%；P 小于 0.01）。总之，exCT 和最有可能的 hCT-M 的血浆浓度非常低（大多数健康成人低于 10 pg/ml），并且在钙输注后总是增加。血浆 exCT 的测量是一种有用的技术，为 hCT 生理学研究提供了新的敏感性和特异性。
To avoid the limitations of present human calcitonin (hCT) assays, we have developed a silica extraction and concentration method for plasma hCT that lowers the detection limit of the assay 40-fold (to 0.5-1.0 pg/ml), and markedly improves specificity of the assay for the CT monomer (hCT-M). Extraction recoveries of radioiodinated and unlabeled synthetic hCT-M added to 20 ml plasma were, respectively, 90 +/- 1% and 99 +/- 4% (mean +/- SE). Gel filtration chromatography of plasma from patients with medullary thyroid carcinoma demonstrated that the extract was markedly enriched in hCT-M. Basal plasma immunoreactive hCT was measured before (iCT) and after extraction (exCT) in 60 normal individuals; basal exCT levels were higher in young men than in young women [8.0 +/- 0.8 (+/- SE) vs. 4.6 +/- 0.5 pg/ml; P less than 0.001] and higher in elderly men than in elderly women (9.4 +/- 0.8 vs. 4.7 +/- 0.6 pg/ml; P less than 0.05), but not different with age. Calcium infusions (2 mg Ca/kg over 5 min) in 36 subjects showed a significantly greater secretory capacity for exCT in men than in women, but showed no decline of exCT response with age. There was no correlation between basal iCT and exCT concentrations, but there was a good correlation between peak Ca-stimulated iCT and peak Ca-stimulated exCT levels (r = 0.94; P less than 0.001), suggesting that hCT-M was the main form released by acute stimulation. The mean extractable CT level in 6 totally thyroidectomized individuals was 2.7 +/- 0.3 pg/ml and did not increase after Ca challenge. We found no significant differences in basal or Ca-stimulated exCT levels measured in 5 women on 3 different occasions over the span of 1 menstrual cycle. After a meal, exCT levels did not change in women, but there was a consistent increase in the men (28 +/- 7% over baseline at 3 h; P less than 0.01). In summary, plasma concentrations of exCT and, most likely, hCT-M were very low (less than 10 pg/ml in most healthy adults) and always increased after calcium infusion. The measurement of plasma exCT is a useful technique that provides new sensitivity and specificity for the study of hCT physiology.