Mayer G P, Habener J F, Potts J T
J Clin Invest. 1976 Mar;57(3):678-83. doi: 10.1172/JCI108324.
The response of normal bovine parathyroid glands to hypercalcemia was assessed in vivo by radioimmunoassay of immunoreactive parathyroid hormone concentrations in parathyroid effluent blood obtained by surgical cannulation of both anesthetized and nonanesthetized calves. Hypercalcemia was induced for periods of 0.3-35 h by intravenous infusion of a solution of calcium chloride. Assessment of immunoreactivity in effluent and peripheral blood included measurements of selected samples by use of a radioimmunoassay specific for a site residing in the biologically active portion of the hormone molecule. In all instances, the concentration of immunoreactive parathyroid hormone in hypercalcemic venous effluent from a superior parathyroid gland exceeded that of the peripheral blood. Failure of hypercalcemia to suppress completely secretion by normal parathyroids indicates that a portion of parathyroid hormone secretion occurs independent of blood calcium concentration. Consequently, continued parathyroid hormone secretion despite hypercalcemia can no longer be regarded as a unique feature of parathyroid neoplasia.
通过对麻醉和未麻醉小牛进行手术插管获取甲状旁腺流出血液,采用放射免疫分析法测定其中免疫反应性甲状旁腺激素浓度,以此在体内评估正常牛甲状旁腺对高钙血症的反应。通过静脉输注氯化钙溶液诱导高钙血症0.3至35小时。对流出血液和外周血中的免疫反应性进行评估,包括使用针对激素分子生物活性部分特定位点的放射免疫分析法对选定样本进行测量。在所有情况下,来自上甲状旁腺的高钙血症静脉流出液中免疫反应性甲状旁腺激素的浓度均超过外周血中的浓度。高钙血症未能完全抑制正常甲状旁腺的分泌,这表明一部分甲状旁腺激素的分泌独立于血钙浓度。因此,尽管存在高钙血症但甲状旁腺激素仍持续分泌,这不再被视为甲状旁腺肿瘤的独特特征。