The Effects Of Different Exercise On Bone Metabolism And PDGF Via ERK Signaling Of Growing Male Mice

Objective:To study the effects of growing male mice based on two exercise modes: downhill running and swimming on bone parameters, including bone mineral density, blood ALP, blood TRACP, bone tissue’s ALP activity, and the mechanism of cell signal pathway of PDGF via ERK through some vital cell factors mRNA and protein. Thus trying to provide some basic theoretical properties for bone remolding by exercise in growing stage.Research methods:The4week old mice were fed in the standard condition in one week before taking different modes of exercise. The48mice were divided into control group (C), swimming group (S), downhill running (R). The downhill running group is in the condition of0.8km/h,45min/day,5days/week. The swimming group is in the condition of swimming pool with45cm level of water in the temperature of30±2degree centigrade. After8weeks of exercise, all of the animals were executed for blood samples and bone tissues.Result:The swimming group BMD is higher than control group, the downhill running group BMD was significantly higher than both control group (P<0.01) and swimming group (P<0.01); The swimming group blood ALP was significantly higher than control group(P<0.01), the downhill running group blood ALP was significantly higher than both control group (P<0.01) and swimming group (P<0.01); The downhill running group TRACP was significantly lower than the control group (P<0.05).The MSCs proliferation ability of downhill running group was higher than swimming group and control group, the MSCs proliferation ability of swimming group was higher than control group; osteoblast regulatory factor BMP-2in downhill running group was significantly higher than both control group(P<0.05), the osteoblast regulatory factor BMP-2in swimming group was significantly higher than control group(P<0.05); the relative expression of cell factors of PDGFb, c-fos, ERK1, Mnkl in downhill running was significantly higher than control group(P<0.05), the relative expression of PDGFb, ERK1in downhill running group was significantly higher than control group(P<0.05), the relative expression of gene factor of c-fos, Mnkl in swimming group was significantly higher than control group(P<0.05); the phosphorylation ERK protein in downhill running group was significantly higher than the control group(P<0.01), the phosphorylation ERK protein in swimming group was significantly higher than the control group(P<0.05).Conclusion:(1) The downhill running is more effectively than swimming on promoting bone metabolism and bone mineral density of growing mice.(2) The downhill running is better than swimming on the proliferation of MSCs.(3) Exercise is an effective way to bone remolding and bone health, by activating the gene expression and protein expression through the pathway of PDGF via ERK cell signals.