Faecal elimination of steroids in rats after oral administration of mepartricin.

Treatment of both male and female rats with 5 IU/day mepartricin for 7-10 days administered by gastric tubing resulted in an increased faecal excretion of some steroids. Mean rate of elimination of total oestrogens was enhanced by 45% in male rats and by 14% in female rats, and the average excretion of conjugated oestrogen was also increased in the female animals. Faecal elimination of cholesterol was 37% and 42% higher in male and female rats, respectively, after mepartricin treatment, and in male rats plasma concentrations of cholesterol were reduced following treatment. It is suggested mepartricin acts either by changing the intestinal flora or by acting directly on the steroid moieties, and it is speculated that a similar mechanism may occur in man.