Effects of mepartricin, a polyene macrolide agent, on fecal excretion and serum concentration of estrogen and number of prostatic estrogen receptors in immature rats

BACKGROUND. Mepartricin, an antifungal agent, was investigated for effects on fecal excretion and serum concentration of sex steroids and the number o f sex steroid prostatic receptors in immature rats. METHODS. Mepartricin was orally administered at 2.5, 5, and 10 mg/kg once d aily for 2 weeks. Fecal estrogen and testosterone excretions, serum estroge n, testosterone and luteinizing hormone concentrations, and numbers of pros tatic estrogen and androgen receptors were assayed. Prostate weight was als o monitored. RESULTS. Fecal estrogen excretion showed a dose-dependent increase, which w as significant for the two higher dosages. Conversely, the serum estrogen c oncentration and prostatic estrogen receptors were significantly decreased. No significant changes in fecal testosterone excretion, serum testosterone and luteinizing hormone concentrations, and prostatic androgen receptors w ere observed. Prostate weight was significantly reduced at 5 mg/kg, but we did not observe dose-dependency. CONCLUSIONS. Mepartricin increases fecal excretion of estrogen by binding w ith it in the intestinal tract, which results in reducing the serum estroge n concentration and number of prostatic estrogen receptors. (C) 1999 Wiley- Liss, Inc.