Effects of Sodium Chloride Supplements and Running Exercise on Bone Metabolism in Rats Fed Low Calcium Diet

Abstract

The effects of dietary supplements of Sodium chloride (8g/100g diet) and voluntary running exercise on bone metabolism were studied in rats fed low calcium diet (0. 012% diet) Sodium chloride supplement significantly reduced weight gain. The mean weight of kidney were significantly increased by intake of Sodium chloride. The mean weight of femur and humerus were significantly lower in the group consuming a low calcium diet. The Sodium chloride supplemented rats exhibited a five-to seven fold increase in urinary calcium excretion, so calcium retention in those groups lost its balauce. There were no differences in breaking force of femur between the groups consuming a low calcium diet and control. However, the breaking force of femur in the group that exercised was significantly lower than that in the sedentary group of the low calcium diet. It is suggested that the low calcium intake restricts the bone formation though voluntary exercise rises bone turnover. The results of this study indicate that dietary Sodium chloride mediate bone loss and that sufficient calcium should be supplied during exercise.