Masuyama R, Uehara M, Suzuki K
Tokyo University of Agriculture, Japan.
Biosci Biotechnol Biochem. 2000 Nov;64(11):2316-9. doi: 10.1271/bbb.64.2316.
To find whether a high phosphorus (P) diet stimulate the secretion of PTH, a high-P diet was fed to rats and an increase in serum P levels has occurred. All rats were fed a control diet (0.5% calcium (Ca), 0.5% P) for 7 days, while they were being adapted, for 1 hour at 8:00 AM and again at 8:00 PM. Four groups were switched to the high-P diet (0.5% Ca, 1.5% P) at the time of their morning meal for 1 hour. The other 4 groups continued to receive the control diet. Blood samples were collected from the rats in the remaining group, which served as a pre-feeding control. Every 30 minutes after the start of feeding (30, 60, 90, 120 min), blood samples were collected from the rats in the groups fed the control and high-P diets. Serum P concentrations increased upon intake of the high P diet, within 30 minutes after the start of feeding. Serum PTH levels also increased upon intake of the high P diet, within 30 minutes after the start of feeding, and the levels were significantly higher in the high-P group than in the control group. However, no significant difference was observed in serum Ca levels between the two groups. From these results, our findings suggest that an increase in serum P concentration might be a trigger of PTH secretion without any changes of serum calcium levels.
为了探究高磷饮食是否会刺激甲状旁腺激素（PTH）的分泌，给大鼠喂食高磷饮食后，血清磷水平出现了升高。所有大鼠在适应期内，每天上午8点和晚上8点各1小时，喂食对照饮食（0.5%钙（Ca），0.5%磷），持续7天。四组大鼠在早餐时改为喂食高磷饮食（0.5% Ca，1.5% P），持续1小时。另外四组继续接受对照饮食。从其余作为喂食前对照的大鼠组采集血样。在开始喂食后每30分钟（30、60、90、120分钟），从喂食对照饮食和高磷饮食的大鼠组采集血样。喂食高磷饮食后，在开始喂食后30分钟内，血清磷浓度升高。喂食高磷饮食后，在开始喂食后30分钟内，血清PTH水平也升高，且高磷组的水平显著高于对照组。然而，两组之间的血清钙水平没有观察到显著差异。从这些结果来看，我们的研究结果表明，血清磷浓度的升高可能是PTH分泌的触发因素，而血清钙水平没有任何变化。
