Specific cytosol binding of diethylstilbestrol in rat skeletal muscle.
Rat skeletal muscle cytosol proteins bound 3H-diethylstilbestrol (3H-DES). More than 90% of this binding was high capacity and low affinity. Serum albumin accounted for roughly 50-60% of the binding, as evidenced by its precipitation with anti-rat albumin IgG. About half of the binding was distinguishable from albumin and other serum proteins by its precipitation in 40% saturated ammonium sulfate. This material sedimented at 4-5S in high-salt sucrose gradients, and resolved into two components (8S and 4-5S) in low-salt. Following incubation at 23-27 degree C for one hour, 2% of the bound 3H-DES in whole cytosol (approximately 2 fmole/Mg cytosol protein) was retained by DNA cellulose, and was eluted with 0.6 M KCl. This small fraction of the total binding was inhibited by estrogens and DES analogues: estradiol-17 beta, DES, dienestrol, and hexestrol were strong inhibitors; isodienestrol, dimethylstilbestrol, estradiol-17 alpha, estrone, tamoxifen, MER-25, CI-628, and nafoxidine were weak inhibitors; dihydrotestosterone, testosterone, and prednisone did not compete. These observations indicate that specific estrogen-binding sites exist in rat skeletal muscle.
D000645:Ammonium Sulfate; D000818:Animals; D011232:Chemical Precipitation; D003600:Cytosol / Q000378:metabolism; D004054:Diethylstilbestrol / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D007163:Immunosorbent Techniques; D009132:Muscles / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012709:Serum Albumin / Q000378:metabolism
D004967:Estrogens; D012709:Serum Albumin; D004054:Diethylstilbestrol; D000645:Ammonium Sulfate