Inhibition of Rat Ovarian 3.BETA.-Hydroxysteroid Dehydrogenase (3.BETA.-HSD), 17.ALPHA.-Hydroxylase and 17, 20 Lyase by Progestins and Danazol.

Arakawa S, S Arakawa, Satoko Arakawa, Mizue Mitsuma, Mitsuma M, M Mitsuma, MASATO IYO, M Iyo, Iyo M, Ohkawa R, Ryoichi Ohkawa, R Ohkawa, A Kambegawa, Akira Kambegawa, Kambegawa A, Okinaga S, Shoichi Okinaga, S Okinaga, Kiyoshi Arai, K Arai, Arai K
Endocrinologia japonica · 1989 · vol. 36(3) , pp. 387–394 · doi:10.1507/endocrj1954.36.387 · PMID:2583058 · W2054696452
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Synthetic progestins and danazol were found to inhibit rat ovarian 3β-HSD, 17α-hydroxylase, and 17,20 lyase enzymes in vitro, with varying potencies.

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This paper investigated how synthetic progestins and danazol affect rat ovarian steroidogenic enzymes by testing, in vitro, the inhibitory effects of norethisterone, levonorgestrel, danazol, gestrinone, desogestrel, and 3-keto-desogestrel on 3β-hydroxysteroid dehydrogenase, 17α-hydroxylase, and 17,20 lyase. Enzyme sources were prepared from ovaries of immature rats stimulated with PMS and hCG (for 3β-HSD) or PMS alone (for 17α-hydroxylase/17,20 lyase), and enzyme activity was measured by quantifying steroid products formed from defined substrates. All tested steroids inhibited 3β-HSD and 17,20 lyase, with particularly marked inhibition for gestrinone and 3-keto-desogestrel on 3β-HSD and for desogestrel and danazol on 17,20 lyase; only desogestrel and danazol inhibited 17α-hydroxylase, with danazol showing much weaker potency (higher Ki). A key caveat is that findings are based on immature-rat ovarian enzyme preparations in vitro rather than direct demonstration in human tissues or clinical settings. This paper is centrally about endometriosis — it studies mechanisms proposed to explain progestins/danazol effects in endometriosis by evaluating direct inhibition of ovarian steroidogenic enzymes.

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Abstract

The site of action of synthetic progestins or danazol in the treatment of endometriosis is considered to be mainly the hypothalamo-pituitary level, but the direct action to the uterine endometrium and the ovary is also suggested. We investigated the effect of these synthetic steroids to rat ovarian steroidogenic enzymes. The effect of norethisterone, levonorgestrel, danazol, gestrinone, desogestrel and 3-keto-desogestrel was studied in vitro. The sources of the enzymes were prepared from ovaries of immature rats treated either with pregnant mare serum gonadotropin (PMS) and human chorionic gonadotropin (hCG) for 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD), or with PMS for 17 alpha-hydroxylase and 17,20 lyase. The substrates used were pregnenolone (P5) for 3 beta-HSD, progesterone (P4) for 17 alpha-hydroxylase, and 17 alpha-hydroxy-progesterone (17 alpha-OH-P4) for 17,20 lyase. The substrates were incubated with the enzyme sources and coenzymes, and the products formed were measured. All the steroids inhibited 3 beta-HSD, and the inhibition by gestrinone (Ki = 3.0 microM) and 3-keto-desogestrel (17.5 microM) was particularly marked. Only desogestrel (Ki = 30.3 microM) and danazol (168 microM) inhibited 17 alpha-hydroxylase. All the steroids inhibited 17,20 lyase, and the inhibition by desogestrel (Ki = 0.70 microM), danazol (0.80 microM), and gestrinone (30 microM) was particularly marked.
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Inhibition of Rat Ovarian 3β-Hydroxysteroid Dehydrogenase (3β-HSD), 17α-Hydroxylase and 17, 20 Lyase by Progestins and Danazol 1989 Volume 36 Issue 3 Pages 387-394 Details Abstract The site of action of synthetic progestins or danazol in the treatment of endometriosis is considered to be mainly the hypothalamo-pituitary level, but the direct action to the uterine endometrium and the ovary is also suggested. We investigated the effect of these synthetic steroids to rat ovarian steroidogenic enzymes. The effect of norethisterone, levonorgestrel, danazol, gestrinone, desogestrel and 3-keto-desogestrel was studied in vitro. The sources of the enzymes were prepared from ovaries of immature rats treated either with pregnant mare serum gonadotropin (PMS) and human chorionic gonadotropin (hCG) for 3β-hydroxy steroid dehydrogenase (3β-HSD), or with PMS for 17α-hydroxylase and 17, 20 lyase. The substrates used were pregnenolone (P5) for 3β-HSD, progesterone (P4) for 17α-hydroxylase, and 17α-hydroxy-progesterone (17α-OH-P4) for 17, 20 lyase. The substrates were incubated with the enzyme sources and coenzymes, and the products formed were measured. All the steroids inhibited 3β-HSD, and the inhibition by gestrinone (Ki= 3.0μEM) and 3-keto-desogestrel (17.5μEM) was particularly marked. Only desogestrel (Ki= 30.3μEM) and danazol (168μEM) inhibited 17α-hydroxylase. All the steroids inhibited 17, 20 lyase, and the inhibition by desogestrel (Ki= 0.70μEM), danazol (0.80μEM), and gestrinone (30μEM) was particularly marked. © The Japan Endocrine Society Favorites & Alerts Recently viewed articles Successor

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endometriosis

MeSH descriptors

3-Hydroxysteroid Dehydrogenases Aldehyde-Lyases Cytochrome P-450 Enzyme Inhibitors Danazol Ovary Pregnadienes Progesterone Congeners Steroid 17-alpha-Hydroxylase Steroid Hydroxylases 3-Hydroxysteroid Dehydrogenases 3-Hydroxysteroid Dehydrogenases Aldehyde-Lyases Aldehyde-Lyases Animals Cytochrome P-450 Enzyme System Cytochrome P-450 Enzyme System Danazol Female Kinetics Ovary

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