Effect of hypothyroidism, diet and litter size on superovulation in the mouse and rat.

Abstract

Summary. Litter size in mice influences the body growth of the young under normal conditions, on inadequate diet and under propylthiouracil (ptu) treatment. Invariably the larger litter size of seven showed poorer growth curves when compared with the litter size of four. A significant increase in the relative ovarian weight was noted in the litter size of four when treated with ptu, but this was not seen in the litter size of seven. No significant differences were noted in the number of ova released in the mice under various conditions of diet, goitrogen administration and litter size. Increasing dosages of goitrogen caused both a decrease in body weight and in ova release in the rat. The number of ova fell from a count of thirty-five in normal rats to eighteen in rats on 0·01% ptu and to no ova in rats on 0 ·05 and 0·1% ptu in the diet.