Distribution of oestrogen-induced peroxidase in the rat uterus

The activity of oestrogen-induced peroxidase in sections along the uterus of normal and mammary tumour-bearing adult rats was measured. Oestradiol increased the activity of this enzyme in the cervix as well as in other parts of the uterus in ovariectomized or immature rats. Peroxidase activity per mg protein was twice as high in the cervix as in the rest of the uterus where it was evenly distributed along both horns. The concentrations of oestrogen receptors in the cytosol and nucleus in each uterine horn and in the cervix was also determined and found to be lower in the cervix than in other sections of the uterus.