THE ELEVATION OF UTERINE β-GLUCURONIDASE ACTIVITY BY ESTROGENIC HORMONES

Abstract

&Glucuronidase is a carbohydrase whose preparation, purification, and properties,' have been described only recently.In 1940,2 indirect evidence was obtained for its probable r&e in vivo, that of catalyzing the synthesis of conjugated glucuronides.At that time, it was observed that the &glucuronidase activity of liver, kidney, and spleen, and not of testis, ovary, uterus, and vagina, increased in animals fed glucuronidogenic substances which were non-estrogenic.It was then suggested that "the enzyme in these sex organs is not concerned primarily in the general detoxication processes of the body, but has some function connected with the metabolism or transport of the sex hormones."In this note we wish to report experiments in which the fl-glucuronidase of various tissues of the mouse was determined after the administration of several of the "natural" estrogenic hormones.In addition, some non-estrogenic glucuronidogenic steroids and terpenes were tested as control substances.Female mice weighing about 20 gm. were ovariectomized, and 21 days later the test substance was injected subcutaneously in a volume of 0.2 ml. of 8 per cent alcohol, twice a day for 3 days.A control group of ovariectomized mice received 8 per cent alcohol alone.All the animals were killed on the 26th day after ovariectomy, when the P-glucuronidase activity of various tissues of each animal was determined, as previously described.2The values obtained for uterus, and in some cases, liver, are compared here with values for the same organs of normal mice (see the table ).The findings may be pointed out: First, the level of the uterine /?-glucuronidase in the control group of thirty-nine ovariectomized animals receiving 8 per cent alcohol alone corresponds to that of the enzyme in the 60 ovariectomized animals receiving non-estrogenic substances.This level is substantially lower than that found in normal mice.In the liver, no change is apparent in the enzyme concentration after ovariectomy.Secondly, in the forty-four ovariectomized mice which received estrogenic