Studies on Chloride of Bone in Cat and Rat. ∗

Abstract

Summary

1) Observations on chloride content of bone of cats and rats revealed, in all but adult rats, that there was more chloride present than would be expected if the entire bone water content was extracellular fluid. This excess was constant at 1.53 meq 100 g of fat free dry bone in the cat over a wide range of water concentrations but, in rats, varied from a similar value in weanlings to the complete absence of an excess in 150-day-old animals. No satisfactory hypothesis could be made concerning the location of this fraction of the total bone chloride. 2) The accuracy of chloride analysis was attested by the maximum variation of 7% between titrometric determinations of chloride and determinations using Br⁸². Studies with Cr⁵¹ revealed that the blood content of well cleaned bone samples contributes less than 5% of the observed chloride and less than 10% of the observed water content.