Bone Abstracts

Osteoporosis is a growing public health problem. As allies have for preventing physical activity, especially resistance training (RT) and hormone replacement. The aim of this study was to analyze the effect of Raloxifene (RLX) and RT in bone metabolism of rats on their aging period. Wistar rats (14–18 months), sham or ovariectomized (OVX) were treated with RLX (1 mg/kg per day) or saline by gavage and subjected to RT or not. The animals were subjected to RT-oriented practice by staircase with 80° tilt, with the overload apparatus corresponding to 20% of strength test and weekly increase 10 until 80% using steel balls in tubes attached at the animals tail. Earlier the 3° and 4° month the maximum strength test was revised to suit the load. After 120 days the start of RT and/or RLX, femurs removed to bone microtomography and immunohistochemistry for Runx2, OSX, OCN, OPG, RANKL and TRAP. For statistical analysis we used a completely randomized design with treatments in a factorial 4×2 crossover and post-Tukey’s test (P<0.05). The morphometric analysis of bone microtomography shows osteopenia, which was more pronounced in animals in groups of OVX rats. The combination treatment resulted in increased bone formation in both groups. However, the group of sham rats that received both therapies showed trabecular bone organized and more consistent than the other experimental groups. Immunostaining for Runx2, OSX and OCN was higher in groups treated with RLX. In the group Sham/RLX/EX, the immunostaining was higher for OPG and RANKL and lower for TRAP. The results of this study reveal that completion of RT, administration of RLX and especially the combination of these triggered increase bone mass in experimental animals and in different degrees reversed the framework of osteopenia.