IRON CONTENT AS A QUANTITATIVE MEASUREMENT OF THE EFFECT OF PREVIOUS PREGNANCIES ON THE MAMMARY GLANDS OF MICE1

Abstract

The iron retention that occurs in the epithelium of the mammary glands of mice has been pointed out (Schultz, ’33; Rawlinson and Hankinson, ’48) (figs. 1–3). Taking advantage of this it is possible to make whole-mount preparations of the glands using an iron stain and thus make a rough assessment of glandular development (Rawlinson, ’50). It seemed likely that the determination of the iron content of such glands by histological and chemical methods would provide a measure of mammary gland development. It was with this object in view that the present experiment was planned. It has been determined by Bittner (who kindly supplied the animals used to found the colony used in this study) that in his subline of C3H mice the cancer incidence in virgin females is 63% as compared with 95% in the breeding females, and that cancers occurred on the average about 4 months earlier in the latter group (Bittner and Huseby, ’46).