Suppression of progestational uterine mucosal activity by anthrarufin.

The effect of anthraquinone derivatives (anthraquinone, sodium anthraquinone T-sulfonate, anthrarufin and enthrone) and other compounds (a-naphthoquinone, lecithin and tannic acid) on progestational proliferation produced by progesterone in the rabbit uterus was investigated by measurements of endometrial carbonic anhydrase activity. In immature rabbits primed with estrogen, the subcutaneous administration of progesterone (2mg/animal for 5 days) caused a typical activation of endometrial carbonic anhydrase. Of the test compounds used, oral treatment with anthrarufin in company with progesterone inhibited the enzyme activation by progesterone. The most effective dose was 1.0mg, causing a 50% inhibition to the action of 2 mg progesterone. When given subcutaneously together with progesterone, anthrarufin caused little or no inhibition of the progesterone-induced enzyme activation. Oral administration of anthraquinone, sodium anthraquinone-fl-sulfonate, a naphthoquinone. lecithin and tannic acid did not interfere with the endometrial response to progesterone. It thus appears that in the rabbit oral administration of anthrarufin causes a significant inhibition of the progesterone-induced increase in endometrial carbonic anhydrase activity and has an antiprogestational action.