Toffaletti J
Transfusion. 1983 Nov-Dec;23(6):471-5. doi: 10.1046/j.1537-2995.1983.23684074265.x.
In order to relate changes in protein-bound and complex-bound calcium to levels of citrate and secretion of parathyroid hormone during mild hypocalcemia, total, ultrafiltrable, and ionized calcium were measured in 13 apparently healthy donors during plateletapheresis. Carboxyl-terminal parathyroid hormone was measured in seven of the donors, and both amino-terminal and intact parathyroid hormone assays were done on one donor. Mean concentrations of total and ionized calcium decreased during most of the procedure, as did total protein, albumin, and phosphorus. Complexed calcium increased, which was attributed to the large increases in citrate levels. Protein-bound calcium decreased more than other forms of calcium, even allowing for the decrease expected from hemodilution. The carboxyl-terminal parathyroid hormone response varied among different donors, but on the average, decreased slightly before gradually rising during the citrate-induced hypocalcemia. These findings suggest that calcium citrate does not affect the secretion of parathyroid hormone, and that at least a portion of protein-bound calcium is readily exchangeable and possibly influenced by the hormone.
为了探究在轻度低钙血症期间蛋白质结合钙和复合物结合钙的变化与柠檬酸盐水平及甲状旁腺激素分泌之间的关系，对13名明显健康的献血者在血小板单采过程中测量了总钙、超滤钙和离子钙。对其中7名献血者测量了羧基末端甲状旁腺激素，对1名献血者进行了氨基末端和完整甲状旁腺激素检测。在大多数操作过程中，总钙和离子钙的平均浓度下降，总蛋白、白蛋白和磷的浓度也下降。结合钙增加，这归因于柠檬酸盐水平的大幅升高。即使考虑到血液稀释预期的下降，蛋白质结合钙的下降幅度也超过其他形式的钙。羧基末端甲状旁腺激素的反应在不同献血者之间有所不同，但平均而言，在柠檬酸盐诱导的低钙血症期间，先略有下降，然后逐渐上升。这些发现表明柠檬酸钙不影响甲状旁腺激素的分泌，并且至少一部分蛋白质结合钙易于交换，可能受该激素影响。
