High-affinity binding of oestradiol-17beta by cytosols from testis interstitial tissue, pituitary, adrenal, liver and accessory sex glands of the male rat.
The specificity of the binding of oestradiol-17beta by cytoplasmic fractions of several tissues of the male rat was investigated. 1. Agar-gel electrophoresis, Sephadex chromatography, adsorption by dextran-coated charcoal and sucrose-gradient centrifugation were used to estimate the binding capacity and specificity. The four different methods all gave similar results for the capacity of the specific oestradiol-17beta-binding macromolecules in the testis. 2. The presence of a specific saturable binding protein with a sedimentation coefficient of 8S was demonstrated in liver, adrenal, pituitary, prostate, epididymis and testis interstitial tissue. The highest concentration of oestradiol-17beta-binding macromolecules was found in testis interstitial tissue (0.12pmol/mg of protein) and in the pituitary (0.075pmol/mg of protein). 3. The oestradiol-17beta receptor in the testis cytosol showed the characteristics of a protein with respect to Pronase treatment and temperature sensitivity. In competition experiments with different steroids the receptor showed a high affinity for oestradiol-17beta, a moderate affinity for diethylstilboestrol and oestradiol-17alpha and a low affinity for oestrone, oestriol, testosterone and 5alpha-dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-one). 4. The wide distribution of oestradiol-17beta receptors in the male rat is in apparent contradiction to the current concept of the specificity of steroid-hormone action. Further research is required to investigate a possible physiological meaning of the presence of specific receptors in the different tissues.
D000311:Adrenal Glands / Q000378:metabolism; D000327:Adsorption; D000818:Animals; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D003600:Cytosol / Q000378:metabolism*; D004586:Electrophoresis; D004822:Epididymis / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D005837:Genitalia, Male / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism; D011402:Pronase; D011467:Prostate / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D011956:Receptors, Cell Surface; D013696:Temperature; D013737:Testis / Q000378:metabolism; D014316:Tritium
D011956:Receptors, Cell Surface; D014316:Tritium; D004958:Estradiol; D011402:Pronase