Direct effect of danazol on the DNA synthesis and ultrastructure of human cultured endometrial stromal cells.

The direct effect of danazol on the DNA synthesis and ultrastructure of human cultured endometrial stromal cells was studied. The analysis of the [3H]thymidine incorporation in the endometrial stromal cells cultured for 10 days indicated that the DNA synthesis was inhibited in a dose-dependent manner by danazol and testosterone, but not by medroxyprogesterone. The effect of 10(-7) M of danazol was blocked by cyproterone acetate, but RU-486 did not show any influence. The observation of the ultrastructure of the cultured cells revealed that 10(-7) M of danazol increased cytoplasmic lysosomes; however, 10(-5) M of danazol destroyed cell organelles and cytoskeleton resulted from the cell death. These results indicated that the biological effects of danazol were mainly mediated by androgen receptors, and 10(-5) M of danazol exhibited the toxic effect on the endometrial stromal cells.