Effects of phosphate-induced hyperparathyroidism and parathyroidectomy on rat kidney calcium in vivo.
Effects of phosphate-induced hyperparathyroidism and parathyroidectomy on rat kidney calcium in vivo.
复制标题
磷酸盐诱导的甲状旁腺功能亢进症和甲状旁腺切除术对大鼠体内肾钙的影响。
DOI：
10.1152/ajpendo.1981.241.2.e136
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Clark,I
中科院分区：
文献类型：
--
作者：
Borle,AB;Clark,I
研究了高磷酸盐饮食对未切除甲状旁腺（PTX）大鼠肾细胞钙代谢的影响。对照组和PTX大鼠分别饲喂钙磷比为2:1的正常饲粮和钙磷比为1:8的高磷饲粮，连续6周（慢性实验）或1、3、6天（急性实验）。采用体外培养肾片的化学和动力学方法研究了肾细胞钙代谢。在对照组大鼠中，高磷酸盐饮食显著增加肾脏和线粒体钙、细胞质和线粒体交换钙池以及所有钙通量。在这些对照组中，血浆磷酸盐没有明显升高，但甲状旁腺激素（PTH）水平趋于高。PTX大鼠给予相同的高磷饲料，血浆磷酸盐显著升高，但肾脏钙代谢未发生变化。这些结果表明，肾钙化症是由PTH水平升高引起的，而不是由血浆磷酸盐升高引起的，肾钙化症发展的第一步是细胞钙代谢和运输的刺激。
The effects of a high-phosphate diet on the calcium metabolism of kidney cells were studied in intact and parathyroidectomized (PTX) rats. The control and the PTX rats were pair-fed a normal diet with a Ca/P of 2:1 or a high-phosphate diet with a Ca/P of 1:8 for 6 wk (chronic experiments) or 1, 3, and 6 days (acute experiments). Renal cell calcium metabolism was studied by chemical and kinetic analyses in kidney slices incubated in vitro. In the control rats the high-phosphate diet significantly increased kidney and mitochondrial calcium, the cytosolic and mitochondrial exchangeable calcium pools, and all calcium fluxes. In these controls, the plasma phosphate was not significantly elevated, but the parathyroid hormone (PTH) levels tended to be high. In PTX rats fed the same high-phosphate diet, the plasma phosphate was significantly elevated, but no change in renal calcium metabolism occurred. These results suggest that nephrocalcinosis was caused by elevated PTH levels and not by the elevated plasma phosphate and that the first step in the development of nephrocalcinosis is a stimulation of cellular calcium metabolism and transport.