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Characterization of a [3H]methyltrienolone (R1881) binding protein in rat liver cytosol.
J Steroid Biochem. 1985 Feb; 22(2):211-9.JS

Abstract

The binding of radiolabelled methyltrienolone 17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-trien-3-one (R1881) to adult male rat liver cytosol has been characterized in the presence of Na-molybdate to stabilize steroid-hormone receptors, and triamcinolone acetonide to block progestin receptors. Using sucrose density gradient analysis, male liver cytosol contains a [3H] R1881 macromolecular complex which sediments in the 8-9S region. 8S binding of R1881 to male rat serum, female liver cytosol or cytosol from a tfm rat cannot be demonstrated. Further metabolism of [3H] R1881 following 20h incubation with male rat liver cytosol was excluded: In the 8S region 97% of [3H] R1881 was recovered by thin layer chromatography. Characteristics of this [3H] R1881-8S binding protein include high affinity (Kd = 2.3 +/- 41 nM) and low binding capacity (18.8 +/- 3.3 fmol/mg cytosol protein), precipitability in 0-33% ammonium sulfate, and translocation to isolated nuclei following in vivo R1881 treatment. Whereas, the cytosol R1881-receptor is competed for by dihydrotestosterone, testosterone, and estradiol, [3H] estradiol binding in the 8S region is not competitive with androgens but does compete with diethylstilbestrol. The nuclear androgen binding site has a Kd = 2.8 nM for [3H] R1881, and is androgen specific (testosterone greater than 5 alpha-dihydrotestosterone greater than estradiol greater than progesterone greater than cyproterone acetate greater than diethylstilbestrol greater than dexamethasone greater than triamcinolone). Since a number of liver proteins including the drug and steroid metabolizing enzymes are, in part, influenced by the sex-hormone milieu, the presence of a specific androgen receptor in male rat liver may provide valuable insight into the regulation of these proteins.

Authors

No affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

3872380

Citation

Levinson, D J., and D E. Decker. "Characterization of a [3H]methyltrienolone (R1881) Binding Protein in Rat Liver Cytosol." Journal of Steroid Biochemistry, vol. 22, no. 2, 1985, pp. 211-9.
Levinson DJ, Decker DE. Characterization of a [3H]methyltrienolone (R1881) binding protein in rat liver cytosol. J Steroid Biochem. 1985;22(2):211-9.
Levinson, D. J., & Decker, D. E. (1985). Characterization of a [3H]methyltrienolone (R1881) binding protein in rat liver cytosol. Journal of Steroid Biochemistry, 22(2), 211-9.
Levinson DJ, Decker DE. Characterization of a [3H]methyltrienolone (R1881) Binding Protein in Rat Liver Cytosol. J Steroid Biochem. 1985;22(2):211-9. PubMed PMID: 3872380.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of a [3H]methyltrienolone (R1881) binding protein in rat liver cytosol. AU - Levinson,D J, AU - Decker,D E, PY - 1985/2/1/pubmed PY - 1985/2/1/medline PY - 1985/2/1/entrez SP - 211 EP - 9 JF - Journal of steroid biochemistry JO - J Steroid Biochem VL - 22 IS - 2 N2 - The binding of radiolabelled methyltrienolone 17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-trien-3-one (R1881) to adult male rat liver cytosol has been characterized in the presence of Na-molybdate to stabilize steroid-hormone receptors, and triamcinolone acetonide to block progestin receptors. Using sucrose density gradient analysis, male liver cytosol contains a [3H] R1881 macromolecular complex which sediments in the 8-9S region. 8S binding of R1881 to male rat serum, female liver cytosol or cytosol from a tfm rat cannot be demonstrated. Further metabolism of [3H] R1881 following 20h incubation with male rat liver cytosol was excluded: In the 8S region 97% of [3H] R1881 was recovered by thin layer chromatography. Characteristics of this [3H] R1881-8S binding protein include high affinity (Kd = 2.3 +/- 41 nM) and low binding capacity (18.8 +/- 3.3 fmol/mg cytosol protein), precipitability in 0-33% ammonium sulfate, and translocation to isolated nuclei following in vivo R1881 treatment. Whereas, the cytosol R1881-receptor is competed for by dihydrotestosterone, testosterone, and estradiol, [3H] estradiol binding in the 8S region is not competitive with androgens but does compete with diethylstilbestrol. The nuclear androgen binding site has a Kd = 2.8 nM for [3H] R1881, and is androgen specific (testosterone greater than 5 alpha-dihydrotestosterone greater than estradiol greater than progesterone greater than cyproterone acetate greater than diethylstilbestrol greater than dexamethasone greater than triamcinolone). Since a number of liver proteins including the drug and steroid metabolizing enzymes are, in part, influenced by the sex-hormone milieu, the presence of a specific androgen receptor in male rat liver may provide valuable insight into the regulation of these proteins. SN - 0022-4731 UR - https://www.unboundmedicine.com/medline/citation/3872380/Characterization_of_a_[3H]methyltrienolone__R1881__binding_protein_in_rat_liver_cytosol_ DB - PRIME DP - Unbound Medicine ER -