Abstract
At the March meeting of this Society, it was shown by Sherman and by one of the writers of this paper that rickets regularly developed in rats maintained on a diet composed of patent flour, calcium lactate, sodium chloride and ferric citrate. It was further found that the substitution of 0.4 per cent. basic potassium phosphate for an equal percentage of calcium lactate in this diet (No. 84), uniformly protected against the development of rickets.
These experiments have been continued. The diet has been modified in various ways, and we wish this evening to report very briefly some of the results obtained.
The basic rickets-producing diet has been tested on a further series of rats, amongst them controls for other experiments. Including the 15 rats referred to in the previous paper, 36 rats in all have been observed to develop rickets upon Diet 84. A few of these after having shown unmistakable rachitic changes by x-ray, were subsequently given other diets. In all the other rats, the diagnosis has been confirmed by microscopic examination. It may be confidently stated then that rickets will develop in 100 per cent. of animals upon this diet; at least, in our experience, there have been no exceptions.
The protective action of the basic potassium phosphate has also been demonstrated in 9 additional rats; and there have been no failures amongst the total 24 rats, which have been studied up to date.
The first question to be answered was as to the part played by the potassium and the phosphate respectively, in the protection afforded by the basic potassium phosphate. To determine this point, an equivalent amount of primary sodium phosphate was substituted for the potassium salt in the diet; and in another series of the same litter, an equivalent amount of potassium chloride for the potassium phosphate.
Get full access to this article
View all access options for this article.