Studies on the Relationship between Bone Strength and Bone Quality in Rats Fed with a Low-magnesium Diet

Abstract

The relationship between bone strength and bone quality in rats fed with a low-magnesium (low-Mg) diet was examined. Twenty four-week-old male Wistar rats were divided into a control group (n = 10) and a low-Mg group (n = 10). Each group was fed with a conventional diet or a low-Mg diet (Mg, 6 mg/100 g diet) for 8 weeks, respectively. After the rats were sacrificed, bone strength, bone mineral content (BMC) and three-dimensional (3D) trabecular structure of the lumbar vertebra were measured, respectively. The results showed that the values of the BMC were almost the same between the control and the low-Mg diet groups. On the other hand, the bone strength of the low-Mg diet group was significantly lower than that of the control group (p < 0.01). 3D trabecular structure analysis showed a significant decrease (p < 0.05 or 0.01) in the trabecular structure of the low-Mg diet group as compared to the control group. These findings suggest that the bone strength in this model is not affected by the BMC but is strongly affected by the trabecular structure. The low-Mg diet model is considered to be an excellent model for examining bone quality.