Measurement of 1,25(OH)_2D_3 receptors in vitamin D resistant diseases.

我们在10例维生素D抗性佝偻病的pha激活的外周单个核细胞中测量了125 (OH)_2D_3受体的特异性结合能力。与正常对照组（57.3 4.9）相比，未补充磷酸盐的患者的结合力明显降低（21.7 5.1 fmol/mg蛋白质，平均SE）。相反，补充组患者（58.3 2.7）与对照组无显著差异。在两例患者中，在开始每日补充磷酸盐后，结合力增加。结合力与血清磷酸盐呈显著正相关（p<0.05）。但与血清钙、血清维生素D代谢物及血浆甲状旁腺激素均无相关性。这些结果表明，持久性低磷血症继发的1,25(OH)_2D_3受体结合能力下降是维生素D抗性佝偻病维生素D抗性的原因之一。

We measured the specific binding capacity of 1,25(OH)_2D_3 receptors in PHA-activated peripheral mononuclear cells from 10 vitamin D resistant rickets. Patients without phosphate supplementation showed significantly lower binding capacity (21.7 5.1 fmol/mg protein, mean SE) compared to the normal controls(57.3 4.9). On the contrary, there was no significant difference between the supplemented patients (58.3 2.7) and controls. In two patients, the binding capacity was increased after daily phosphate supplementation was started. Moreover, there was a significant positive correlation between binding capacity and serum phosphate (p<0.05). But no correlation was found with serum calcium, serum vitamin D metabolites nor plasma parathyroid hormone. These results indicate that a decreased binding capacity of 1,25(OH)_2D_3 receptors secondary to persistent hypophosphatemia is one of the causes of vitamin D-resistance in vitamin D resistant rickets.