Effect of exercise on the bone strength, bone mineral density, and metal content in rat femurs

Article type: Research Article

Authors: Chen, X.^; | Aoki, H. | Fukui, Y.

Affiliations: Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama, 350‐0394, Japan | Frontier Research and Development Center, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama, 350‐0394, Japan

Note: [] Corresponding author. Tel.: +81 (0) 49 296 2911(3752); Fax: +81 (0) 49 296 2925; E‐mail: [email protected].

Abstract: We have investigated the effect of exercise on the bone strength, bone mineral density (BMD), and metal content in rat femurs. Five Wister rats acting as an exercised group (E group) were exercised at intervals on a treadmill every day for four weeks. Another five rats were fed in a cage, acting as a control group (C group), without any exercise. After four weeks, the bend strength, Young's modulus, BMD value, and metal content of the femurs were measured using a three‐point bend test, Dual‐Energy X‐ray Absorptiometry (DEXA), and chemical analysis. The bend strength of the E group was 101±5 MPa, and that of the C group was 86±7 MPa. The Young's modulus was 1.16±0.03 GPa for the E group, and 0.98±0.06 GPa for the C group. The BMD values were 0.179±0.002 g/cm2 for the E group, and 0.166±0.002 g/cm2 for the C group. The Ca concentration was 230,600 ± 1,500 μg/g for the E group, and 223,000 ± 2,700 μg/g for the C group. The Zn concentration was 160 ± 7 μg/g for the E group, and 188 ± 8 μg/g for the C group.

Keywords: Exercise, rat femurs, bone strength, BMD, metal mineral content

Journal: Bio-Medical Materials and Engineering, vol. 14, no. 1, pp. 53-59, 2004