A COMPARISON OF BONE GROWTH IN NORMAL AND STRONTIUM-TREATED RATS

¹ National Institute of Dental Research, National Institutes of Health, Public Health Service, U. S. Department of Health, Education and Welfare, Bethesda, Md.

The influence of a strontium supplement on bone growth was studied in male, Osborne-Mendel rats of an inbred strain over periods of 90 and 180 days postweaning.

1. Rates of longitudinal and transverse growth, gains in breaking strength and mineral component of the tubular bones showed no evidence of abnormality in the rats which had received strontium.

2. Both control and test animals showed a decidedly reduced rate of accumulation of ingested strontium in various long bones during 90 to 180 days postweaning.

3. The postweaning per cent gain in breaking strength of the tubular bones is remarkable, being 20 times the per cent increase in length after 90 days.

4. Growth in length, volume, strength, and ash of the long bones showed a twofold ratio between the logarithms of the respective per cent increases in these quantities for the first 3 months postweaning versus the succeeding 3 months.

5. Procedures are described for measuring the total volume of small animal bones with a precision averaging better than ± 0.002 ml. and for determining the relative breaking strengths of small bones with an average absolute deviation of less than 6 per cent.