Matsuzaki Hiroshi, Katsumata Shinichi, Maeda Yoshiaki, Kajita Yasutaka
Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan, Department of Food and Nutritional Science, Graduate School of Agriculture, Graduate School of Tokyo University of Agriculture, Tokyo 156-8502, Japan.
Department of Food and Nutritional Science, Graduate School of Agriculture, Graduate School of Tokyo University of Agriculture, Tokyo 156-8502, Japan.
Magnes Res. 2016 Jun 1;29(2):48-54. doi: 10.1684/mrh.2016.0401.
Fibroblast growth factor 23 (FGF23) is a potent regulator of phosphorus (P) and vitamin D metabolism. Long-term dietary magnesium (Mg) deficiency increases circulating levels of FGF23, whereas the effects of short-term dietary Mg deficiency are unclear. Thus, the present study investigated whether short-term dietary Mg deficiency affects circulating levels of FGF23. We also assessed changes in renal mRNA expression of vitamin D metabolizing enzymes and type II sodium-phosphate (Na/Pi) cotransporters, since these are regulated by FGF23. Rats were fed a control diet (control group) or an Mg-deficient diet (Mg-deficient group) for 2, 4 or 7 days. Serum Mg levels were significantly lower in the Mg-deficient group than in the control group at all time points. Serum FGF23 levels were significantly higher in the Mg-deficient group than in the control group at day 7. The 25-hydroxyvitamin D-24-hydroxylase (24(OH)ase) mRNA levels were significantly higher in the Mg-deficient group than in the control group at day 7 . No significant differences in types IIa and IIc Na/Pi cotransporter mRNA levels were observed between the control and Mg-deficient groups. These results suggest that dietary Mg deficiency causes a rapid increase in circulating levels of FGF23 and renal 24(OH)ase mRNA levels.
成纤维细胞生长因子23（FGF23）是磷（P）和维生素D代谢的有效调节因子。长期膳食镁（Mg）缺乏会增加FGF23的循环水平，而短期膳食镁缺乏的影响尚不清楚。因此，本研究调查了短期膳食镁缺乏是否会影响FGF23的循环水平。我们还评估了维生素D代谢酶和II型钠磷（Na/Pi）共转运蛋白的肾脏mRNA表达变化，因为这些受FGF23调节。将大鼠喂食对照饮食（对照组）或缺镁饮食（缺镁组）2、4或7天。在所有时间点，缺镁组的血清镁水平均显著低于对照组。在第7天，缺镁组的血清FGF23水平显著高于对照组。在第7天，缺镁组的25-羟基维生素D-24-羟化酶（24(OH)ase）mRNA水平显著高于对照组。对照组和缺镁组之间未观察到IIa型和IIc型Na/Pi共转运蛋白mRNA水平的显著差异。这些结果表明，膳食镁缺乏会导致FGF23循环水平和肾脏24(OH)ase mRNA水平迅速升高。
