Bone Abstracts

Objective: We investigated the effect of arginine administered for 10 weeks in diet on bone metabolism in male Wistar rats.

Methods: Rats were divided (after approval of Ethical Committee 9814/2008-30 and 30793/2010-30) into four groups, ten animals in each group: G1 SLD-S group were fed a standard laboratory diet (SLD). G2 SLD-H group were fed SLD and 12 h before rats were sacrificed diet was removed. G3 ARG-S group was fed with 10% arginine (ARG) enriched SLD. G4 ARG-H were fed ARG and 12 h before rats were sacrificed was diet removed. The bone mineral density (BMD, g/cm²) was determined using dual-energy X-ray absorptiometry. The femurs were used for biomechanical testing. Bone marker concentrations were examined: N-terminal propeptide of procollagen (PINP; pg/ml), bone morphogenetic protein 2 (BMP2; pg/ml) and factor (IGF; pg/ml) in bone homogenate using the ELISA method. Results are expressed as the mean or median.

Results: No significant differences of BMD were observed between groups, the decrease in adipose tissue mass was observed in both fasted groups (G1, 75; G2, 51; G3, 57; and G4, 49). The forces necessary to fracture left tibia were not significantly lower in ARG fed rats (G1, 131; G2, 126; G3, 109; and G4, 120). Higher PINP values in both groups (SLD and ARG) have been found after fasting (median G1, 151; G2, 155; G3, 139; and G4, 147). Moreover in other indicators were no differences between groups SLD and ARG, but differences were observed between fed and starving rats. There was increase in IGF (G1, 1387; G2, 1497; G3, 905; and G4, 5189).

Conclusion: Short-fasting affect bone metabolism and fat tissue mass in rats. Effects of diets enriched with arginine only marginally decreased resistance to the three-point tibial fracture.

Acknowledgements

Research project PRVOUK 37/11 Charles University in Prague, SVV-2013 266902.