Distribution of antiestrogen-specific binding sites in normal and neoplastic mammary gland
Autor: | Richard C. Moon, Rajendra G. Mehta, Wendy L. Cerny |
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Rok vydání: | 1984 |
Předmět: |
Cancer Research
medicine.medical_specialty Receptors Drug Mammary gland Estrogen receptor macromolecular substances Adenocarcinoma Binding Competitive chemistry.chemical_compound Cytosol Mammary Glands Animal Pregnancy Internal medicine medicine Distribution (pharmacology) Animals Lactation Triphenylethylene Binding site skin and connective tissue diseases Mammary Neoplasms Experimental Rats Inbred Strains General Medicine Antiestrogen Rats Kinetics Tamoxifen medicine.anatomical_structure Endocrinology Oncology chemistry Receptors Estrogen Cytoplasm Cancer research Female hormones hormone substitutes and hormone antagonists medicine.drug |
Zdroj: | Oncology. 41(6) |
ISSN: | 0030-2414 |
Popis: | Recently, several investigators have demonstrated the presence of triphenylethylene antiestrogen binding sites in the cytoplasm of many tissues, which specifically bind to radioactive tamoxifen with high affinity. Although mammary gland is one of the principal target organs for antiestrogen action, the characterization of antiestrogen binding in mammary tissues has not been reported. We have studied the antiestrogen binding properties of [3H]tamoxifen in the mammary glands of virgin, pregnant and lactating rats as well as in the N-methyl-N-nitrosourea-induced mammary tumors. Tritium labeled tamoxifen bound specifically and with high affinity (Kd = 10(-9) M) to components present in 25,000 g supernatant. Unlabeled estradiol or DES did not compete for these sites, whereas unlabeled tamoxifen showed competitive inhibition. The mammary glands contained threefold higher levels of cytoplasmic binding sites as compared to the mammary tumors. Mammary glands from the pregnant rats bound tamoxifen to a greater extent than that of either virgin or lactating rats. The functional relevance of these binding sites is still unknown. |
Databáze: | OpenAIRE |
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