Effects of high phosphorus diet on bone metabolism-related gene expression in young and aged mice

In this study,the effects of high phosphorus (p) diet on bone metabolism-related gene expression were investigated in young and aged mice. twelve- and 80-week-old ddy male mice were divided into two groups,respectively,and fed a control diet containing 0.3% p or a high p diet containing 1.2% p. after 4 weeks of treatment,serum parathyroid hormone (pth) concentration was significantly higher in the high p groups than in the control groups in both young and aged mice and was significantly higher in aged mice than in young mice fed the high p diet. high p diet significantly increased receptor activator of nf-b ligand (rankl) mrna in the femur of both young and aged mice and significantly increased the rankl/osteoprotegerin (opg) mrna ratio only in aged mice. high p diet significantly increased mrna expression of transient receptor potential vanilloid type 6,calbindin-d9k,and plasma membrane ca2+-atpase 1b in the duodenum of both young and aged mice. these results suggest that high p diet increased rankl mrna expression in the femur and calcium absorption-related gene expression in the duodenum regardless of age. furthermore,the high p diet-induced increase in pth secretion might increase the rankl/opg mrna ratio in aged mice. © 2014 shinichi katsumata et al.