DETERMINATION OF SODIUM-TO-CALCIUM RATIO IN MOUSE FEMORA BY INAA

Within the scope of the study of the heteroionic exchange in the bone mineral, the sodium-to-calcium ratio was established in femora of 55 m ale ICR mice. The purpose of the work was to establish the precision o f the method as well as biological variations, since the authors inten d to investigate the sodium-to-calcium ratio on pathophysiological mod els in the future with a special regard to osteoporosis. The resulting mean value was of 0.02515 +/- 0.00053. The small standard deviation i ndicates that the ratio is not subject to considerable individual vari ations. The accuracy of the method was checked by analyzing the refere nce bone sample IAEA H-5. The results obtained exerted a good agreemen t with the certified sodium and calcium concentrations.