The effects of estrogen and progesterone on glycogen and the enzymes involved in its metabolism in the cat uterus.

In the endometrium of the spay cat, estradiol treatment causes a drastic reduction in glycogen content. The initiation of simultaneous progesterone treatment causes a replenishment of glycogen with the levels surpassing those observed in the spayed animal. The effect of the hormones on glycogen synthetase I follows the same pattern as the changes in glycogen content, while the effect on phosphorylase a is the mirror image. The total content of glycogen synthetase and phosphorylase do not show appreciable changes with the same hormone treatment. The possible reproductive role of these changes in glycogen content are discussed.