ethisterone and 2-(hydroxymethyl)ethisterone

Danazol and gestrinone are both effective agents in the treatment of endometriosis. Their mechanism of action is unknown but may be related to their androgenic activity, which is at least partly dependent on increases in the proportion of testosterone which circulates unbound to plasma protein. We have quantified these increases in patients on treatment, and by experimentation in vitro have demonstrated the relative importance of the reduction of sex hormone binding globulin (SHBG) binding capacity and competition with testosterone for SHBG binding sites by the drugs and some of their metabolites. The mean SHBG binding capacity in patients treated with danazol (400 mg/d, n = 7) and gestrinone (5 mg/week, n = 7) fell from 66.9 and 56.4 nmol/l to 36.1 and 28.1 nmol/l, after 1 week's treatment and to 11.1 and 7.1 nmol/l after 4 weeks respectively. Despite the similarity between the falls in SHBG binding capacity there was a significantly greater increase in % free testosterone in plasma samples from patients treated with danazol than in those from patients treated with gestrinone at 1 week. Experiments in vitro suggest that this was largely due to ethisterone (a major metabolite of danazol) competing with testosterone for SHBG binding sites. After 4 weeks on treatment there was a similar, near maximal reduction in SHBG binding of testosterone in both treatment groups. At the low levels of SHBG binding capacity reached by this time the extra effect of any competition for binding sites was much reduced.

Topics: Danazol; Ethisterone; Female; Gestrinone; Humans; In Vitro Techniques; Norpregnatrienes; Pregnadienes; Protein Binding; Sex Hormone-Binding Globulin; Testosterone

To investigate the changes in the serum androgen concentrations and the Free Androgen Index (FAI) in women during danazol therapy, we measured the serum concentrations of adrenal steroids and danazol metabolites, and then examined the effects of danazol metabolites on assays for serum androgens. Thirteen women who had endometriosis were treated with danazol (300 or 400 mg/day) for 8 to 16 weeks. Blood samples were taken before, during, and after the medication. During the danazol therapy, serum testosterone (T), cortisol (F), and sex-hormone binding globulin (SHBG) significantly decreased (P < 0.05); but serum dehydroepiandrosterone-sulfate (DHEAS) and FAI increased (P < 0.05). The serum concentrations of danazol metabolites were: danazol, 209.0 +/- 28.3 (ng/mL, mean +/- SEM); delta 1-2-hydroxymethyl ethisterone, 114.4 +/- 8.4; and 2-hydroxymethyl ethisterone, 660.0 +/- 54.2. There was considerable cross-reaction between danazol metabolites and androgens [T, androstenedione (A), and dehydroepiandrosterone (DHEA)] in the direct assays. As for the ratios of adrenal steroids in serum, the DHEAS/F, DHEAS/DHEA, and 11-deoxycortisol (S)/F ratios increased (P < 0.05). We conclude that the increase in FAI and DHEAS represents increased native androgenic activity with danazol, and the changes in adrenal steroid ratios in serum indicate the inhibition of 11 beta-hydroxylase and sulfatase activities during danazol therapy.

Topics: Adrenal Glands; Adult; Age Factors; Androgens; Arylsulfatases; Cortodoxone; Danazol; Dehydroepiandrosterone; Dehydroepiandrosterone Sulfate; Endometriosis; Ethisterone; Female; Humans; Hydrocortisone; Middle Aged; Sex Hormone-Binding Globulin; Steroid 11-beta-Hydroxylase; Steryl-Sulfatase; Testosterone

Topics: Chromatography, High Pressure Liquid; Danazol; Endometriosis; Ethisterone; Female; Humans; Pregnadienes

Danazol and gestrinone are effective drugs in the treatment of endometriosis. Their mechanism of action remains uncertain, but may be related to their androgenic activity. The authors examined the effect of danazol on human endometrial cells cultured in vitro, its two major metabolites, ethisterone and 2 hydroxymethyl ethisterone, gestrinone, and testosterone (T) at 1X and 10X expected plasma concentrations. Danazol and T suppressed growth by 20.8 and 25.0% (P less than 0.01), respectively, at the lower dose, and by 26.9 and 35.5% (P less than 0.01), respectively, at the 10-fold higher dose. No significant suppression of growth occurred with gestrinone, ethisterone, or 2 hydroxymethyl ethisterone. The results provide further evidence that danazol and T (but not gestrinone) may act by a direct effect on endometrial tissue.

Topics: Cell Division; Cells, Cultured; Danazol; Endometrium; Ethisterone; Female; Gestrinone; Humans; In Vitro Techniques; Norpregnatrienes; Pregnadienes; Testosterone