Advertisement

Klinische Wochenschrift

, Volume 64, Issue 16, pp 732–737 | Cite as

Inhibition of androgen receptor binding by natural and synthetic steroids in cultured human genital skin fibroblasts

  • M. Breiner
  • G. Romalo
  • H. -U. Schweikert
Originals

Summary

The ability of various natural and synthetic steroids (some of which are widely used in clinical practice) to compete with dihydrotestosterone receptor binding in human genital skin fibroblasts was studied. Binding was assessed in fibroblast monolayers after incubation for 1 h at 37 °C with 2 nM3H-dihydrotestosterone in the presence or absence of increasing concentrations of the steroid to be tested. Inhibition constants (Ki) were determined as the concentration of competitor-required for 50% inhibition of3H-dihydrotestosterone binding. In addition, relative binding activity (RBA) of each test compound was calculated. Each competitor was tested in at least two different cell strains. The concentrations of unlabeled methyltrienolone (a synthetic nonmetabolizable androgen) and dihydrotestosterone for 50% inhibition of3H-dihydrotestosterone binding were in the same order of magnitude, namely, 2 nM (2.2 respectively, 2.4 nM), whereas the affinity of testosterone was approximately one-fifth that of dihydrotestosterone.

Other potent competitors for dihydrotestosterone binding were three progestins (norgestrel, gestoden, and medroxyprogesterone acetate) which have Ki values similar to testosterone. An order of magnitude lower Ki values (around 10−7M) were found for the androgen 17α-propylmesterolone, the antiandrogen cyproterone acetate, and the progestin norethisterone acetate. Binding affinities of all other steroids to the androgen receptor were markedly lower and showed the following order of potency: estrogens (estradiol, ethinyl estradiol, diethylstilbestrol) > glucocorticoids as well as aromatase inhibitors and potassium canrenoate. We conclude that (a) among the compounds tested some progestins are very potent in their ability to interact with human skin fibroblast receptors and thus may affect endogenous androgen action; (b) estrogens are relatively weak androgen receptor binders; and (c) this receptor assay in combination with pharmacokinetic and metabolic studies appears to be a useful screening test to evaluate the potency of various steroids for androgen and antiandrogen therapy.

Key words

Human fibroblasts Androgen binding Inhibition of androgen binding Steroids 

Abbreviations

DHT

5α-dihydrotestosterone

EMM

Eagle's minimum essential medium

FCS

Fetal calf serum

RBA

Relative binding activity

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Brown TR, Migeon CJ (1981) Cultured human skin fibroblasts: a model for the study of androgen action. Mol Cell Biochem 36:3–22Google Scholar
  2. 2.
    Brown TR, Rothwell SW, Migeon CJ (1981) Comparison of methyl trienolone and dihydrotestosterone binding and metabolism in human genital skin fibroblasts. J Steroid Biochem 14:1013–1022Google Scholar
  3. 3.
    Brown TR, Rothwell SW, Sultan C, Migeon CJ (1981) Inhibition of androgen binding in human foreskin fibroblasts by antiandrogens. Steroids 37:635–648Google Scholar
  4. 4.
    Corvol P, Michaud A, Menard J, Freifeld M, Mahoudeau J (1975) Antiandrogenic effect of spironolactones: mechanism of action. Endocrinology 97:52–58Google Scholar
  5. 5.
    Cunningham GR, Lobl TJ, Cockrell C, Shao TC, Tindall DJ (1983) Characterization of steroid binding specificity of the androgen receptor in human skin fibroblasts. Steroids 41:617–626Google Scholar
  6. 6.
    Griffin JE, Wilson JD (1980) The syndromes of androgen resistance. N Engl J Med 302:198–209Google Scholar
  7. 7.
    Eil C, Edelson SK (1984) The use of human skin fibroblasts to obtain potency estimates of drug binding to androgen receptors. J Clin Endocrinol Metab 59:51–55Google Scholar
  8. 8.
    Keenan BS, McNeel RL, Gonzales ET (1984) Abnormalities of intracellular 5α-dihydrotestosterone binding in simple hypospadias: studies in equilibrium steroid binding in sonicates of genital skin fibroblasts. Pediatr Res 18:246–220Google Scholar
  9. 9.
    Lamberigts G, Dierickx P, De Moor P, Verhoeven G (1979) Comparison of the metabolism and receptor binding of testosterone and 17β-hydroxy-5α-androstan-3-one in normal skin fibroblasts cultures: influence of origin and passage number. J Clin Endocrinol Metab 48:924–930Google Scholar
  10. 10.
    Lowry OH, Rosebrough NJ, Randall RH, Farr AL (1951) Protein measurement with the folin phenol reagent. J Biol Chem 193:265–275Google Scholar
  11. 11.
    Mowszowicz J, Riahi M, Wright F, Bouchard P, Kuttenn F, Mauvais-Jarvis P (1981) Androgen receptor in human skin cytosol. J Clin Endocrinol Metab 52:338–344Google Scholar
  12. 12.
    Schweikert HU (1979) Conversion of androstenedione to estrone in human fibroblasts cultured from prostate, genital and nongenital skin. Horm Metab Res 11:635–640Google Scholar
  13. 13.
    Schweikert HU, Milewich L, Wilson JD (1976) Aromatization of androstenedione by cultured human fibroblasts. J Clin Endocrinol Metab 43:785–795Google Scholar
  14. 14.
    Schweikert HU, Hein HJ, Romijn JC, Schröder FH (1982) Testosterone metabolism of fibroblasts grown from prostatic carcinoma, benign prostatic hyperplasia and skin fibroblasts. J Urol 127:361–367Google Scholar
  15. 15.
    Schweikert HU, Knauf W, Romalo G (1984) Androgen binding in cultured human fibroblasts from patients with idiopathic hypospadias. 7th International Congress of Endocrinology, Quebec, Canada. Abstracts, Excerpta Medica, Amsterdam, p 1470Google Scholar
  16. 16.
    Shapiro G, Evron S (1980) A novel use of spironolactone. Treatment of hirsutism. J Clin Endocrinol Metab 51:429–432Google Scholar
  17. 17.
    Wilbert DM, Griffin JE, Wilson JD (1983) Characterization of the cytosol androgen receptor of the human prostate. J Clin Endocrinol Metab 56:113–120Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • M. Breiner
    • 1
  • G. Romalo
    • 1
  • H. -U. Schweikert
    • 1
  1. 1.Medizinische Universitäts-Poliklinik BonnGermany

Personalised recommendations