Estrone – a partial estradiol antagonist in the normal breast
| Autor: | Peter Conner, Sabine Naessén, Eva Lundström, Gunnar Söderqvist, Kjell Carlström, L. Löfgren |
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| Rok vydání: | 2015 |
| Předmět: |
Agonist
medicine.medical_specialty Estrone medicine.drug_class Endocrinology Diabetes and Metabolism medicine.medical_treatment Estrogen receptor Breast Neoplasms chemistry.chemical_compound Endocrinology In vivo Internal medicine medicine Humans Breast Mammary Glands Human Aged Breast Density Estradiol Estriol Estrogen Replacement Therapy Estrogen Antagonists Antagonist Obstetrics and Gynecology Hormone replacement therapy (menopause) Middle Aged Norethisterone acetate Drug Combinations chemistry Female Norethindrone Normal breast Contraceptives Oral Mammography medicine.drug |
| Zdroj: | Gynecological Endocrinology. 31:747-749 |
| ISSN: | 1473-0766 0951-3590 |
| DOI: | 10.3109/09513590.2015.1062866 |
| Popis: | Oral hormone replacement therapy (HRT) based on estradiol-17β (E2) greatly increases circulating estrone (E1) levels. E1 is an estrogen receptor agonist but may also be a partial E2 antagonist. We investigated the effects of circulating E1 on the association between circulating E2 and the increase in mammographic density (∂MD) in 46 healthy post-menopausal women treated with E2 2 mg and norethisterone acetate 1 mg daily. MD and serum E1 and E2 were measured before and after 6 months of treatment. At high E1 levels, ∂MD showed significant positive correlations leading to increase (∂-values) in both E1 and E2. Lowering the upper serum E1 limit strengthened the correlations to ∂E2 while the significant correlations to ∂E1 disappeared. E1 at high concentrations may act as a partial E2 antagonist also in the normal breast in vivo and disturb relationships between circulating E2 and biological estrogen effects. When investigating the relations between circulating steroids and their effects, structurally related compounds, which may act as partial antagonists, have to be considered, at least when they are present in higher concentrations. |
| Databáze: | OpenAIRE |
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