The action of hormones on the rat uterus and mammary gland gamma-glutamyltranspeptidase activity.

The gamma-glutamyltranspeptidase activity of rat uterus and mammary gland was studied in ovariectomized, hypophysectomized and ovariectomized-hypophysectomized rats under different hormonal and drug treatments. The uterine enzyme appears to be mainly dependent on a direct action of estradiol and the mammary gland enzymatic activity is dependent on prolactin. Our result, however, do not exclude a possible role of estradiol in the regulation of prolactin effects on mammary gland enzymatic activity.