Kawase M, Tsuda M, Matsuo T
Biology Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan.
J Bone Miner Res. 1989 Jun;4(3):359-64. doi: 10.1002/jbmr.5650040310.
Age-associated changes in the femoral bone and in urine and serum composition were studied to understand the low bone mass in a substrain of senescence-accelerated mouse (SAM), SAM-P/6. Age-matched normal SAM-R/1 mice were used as controls. After 13 weeks of age, the concentration of hydroxyproline in the femur of SAM-P/6 was slightly but significantly lower. The urinary excretion rates of cAMP and calcium were higher in SAM-P/6 throughout the whole experimental period, and those of hydroxyproline and phosphorus were higher after 8 weeks. The serum concentrations of calcium and inorganic phosphorus of SAM-P/6 were higher at 13 and 20 weeks. At 5 weeks, the serum alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP) activities of SAM-P/6 were significantly higher. Furthermore, the serum of SAM-P/6 significantly stimulated calcium release from cultured fetal rat ulna. Since urinary cAMP and TRAP in the serum reflect the circulating level of parathyroid hormone and osteoclastic function, respectively, the present results suggest that, in SAM-P/6, accelerated bone resorption produced by a putative hyperparathyroid state causes the decrease in bone mass.
为了解衰老加速小鼠（SAM）的一个亚系SAM-P/6的低骨量情况，研究了股骨以及尿液和血清成分随年龄的变化。将年龄匹配的正常SAM-R/1小鼠用作对照。13周龄后，SAM-P/6股骨中的羟脯氨酸浓度略有下降，但差异显著。在整个实验期间，SAM-P/6的尿中环磷酸腺苷（cAMP）和钙的排泄率较高，8周后羟脯氨酸和磷的排泄率较高。SAM-P/6在13周和20周时血清钙和无机磷浓度较高。在5周时，SAM-P/6的血清碱性磷酸酶和抗酒石酸酸性磷酸酶（TRAP）活性显著升高。此外，SAM-P/6的血清显著刺激培养的胎鼠尺骨释放钙。由于尿中的cAMP和血清中的TRAP分别反映甲状旁腺激素的循环水平和破骨细胞功能，目前的结果表明，在SAM-P/6中，假定的甲状旁腺功能亢进状态导致的骨吸收加速会引起骨量减少。
