caa a22 4500 386389411 CHVBK 20180307112109.0 cr unu---uuuuu 161130s1989 xx s 000 0 eng 10.1017/S0269727000010666 doi S0269727000010666 pii (NATIONALLICENCE)cambridge-10.1017/S0269727000010666 Oestrogen uptake and metabolism in vivo [Elektronische Daten] Uptake of oestrogens into breast tissue and their subsequent metabolism can be studied by infusing radio-labelled steroids into volunteer patients. Such studies show that oestradiol is preferentially accumulated in breast tumours, oestradiol concentrations exceeding those of oestrone. This contrasts with plasma, in which oestrone concentrations in postmenopausal women are greater than those of the oestradiol. This observation suggests that tissue factors can modulate local oestrogen metabolism, and thus local steroid concentrations. We have studied the local production of oestrogens from androgen, and also the interconversion of the major oestrogens, oestrone and oestradiol. Using isotopic techniques, it is possible to calculate the proportion of endogenous oestrogen produced from androgen, as opposed to uptake from the circulation. These studies suggest that a very variable proportion of tissue oestrogen derives from endogenous synthesis. After administration of aromatase inhibitors, aromatase activity is substantially inhibited, both in vivo and in vitro. Relative oestrogen concentrations are determined in part by the activity of oestradiol dehydrogenase. In breast tissue, dehydrogenase activity is present and this is modified by various factors, including androgens. In addition, we have demonstrated that normal, benign and malignant breast tissues produce factors which can modulate both growth and dehydrogenase activity of cancer cells in vitro. We conclude that breast tissue is a site of synthesis of oestrogens, and that a number of factors can affect their local concentration. Tumour cells produce growth factors which can influence steroid metabolism, and may thus be able to enhance favourably their own endocrine environment. Copyright © Royal Society of Edinburgh 1989 Local Oestrogen Metabolism nationallicence James V. H. T. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Reed M. J. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Adams E. F. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Ghilchick M. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Lai L. C. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Coldham N. G. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Newton C. J. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Purohit A. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Owen A. M. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Singh A. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Islam S. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K. Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences Royal Society of Edinburgh Scotland Foundation 95(1989), 185-193 0269-7270 95<185 1989 95 PRB https://doi.org/10.1017/S0269727000010666 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0269727000010666 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- James V. H. T. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Reed M. J. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Adams E. F. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Ghilchick M. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Lai L. C. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Coldham N. G. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Newton C. J. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Purohit A. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Owen A. M. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Singh A. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 700 1- Islam S. Department of Chemical Pathology, St Mary's Hospital Medical School, London W2 1PG, U.K NATIONALLICENCE 773 0- Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences Royal Society of Edinburgh Scotland Foundation 95(1989), 185-193 0269-7270 95<185 1989 95 PRB CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge