Oestrogen actions

Quinestrol Synthetic oestrogen, with prolonged duration of action Oestrogen deficiency... [Pg.17]

More subtle modes of action are also possible since the response to hormone receptor binding is complex and could be affected by chemical interference with receptor-related proteins, DNA methylation or histone acetylation. Dioxin (TCDD), for example, reduces the ability of the oestrogen-receptor complex to bind to the oestrogen response element of DNA, reducing gene transcription. ... [Pg.12]

The responsiveness of a tissue to a hormone depends on the density of receptors within its component cells. The number of receptors is determined by their rate of synthesis and catabolism, which is itself controlled by complex feedback mechanisms involving hormone action. Some chemicals are known to interfere with this regulation. For example, TCDD can act to increase or decrease the expression of the oestrogen receptor. ... [Pg.13]

Sites of Oestrogen Action and Production in the Male Reproductive Tract... [Pg.96]

Oestrogen action is mediated through specific receptors localised within the nucleus of target cells (see Carson-Jurnica et and Tsai and O Malley " for... [Pg.96]

Bastenie and Zylberszac, in a general article on the former subject, point out that colchicine (1) brings into mitosis all cells which are in karyo-kinetic inuninence but which normally would slowly and successively reach mitosis, and (2) stops them at this stage. This has made possible a technique which picks out cell multiplication and can be used for detecting many types of hormonal stimulation, e.g., the action of follicular hormone and other oestrogens. ... [Pg.657]

Testosterone represents the immediate precursor of the oestrogens, the conversion being catalysed by the aromatase complex, i.e. a microsomal enzyme system. The biological actions of oestrogens may be summarized as ... [Pg.317]

Docke F, Ledwon P, Sturzebecher B, Rohde W, Dorner G (1989) Oestrogen priming for the positive oestrogen feedback site of action. Exp Clin Endocrinol 94 55-60... [Pg.141]

Docke F, Rohde W, Sturzebecher B, Ledwon P, Dorner G (1990) Evidence that desensitization of the negative feedback of oestrogen and priming for the positive feedback of oestrogen depend upon a common mechanism of oestrogen action in rats. J Endocrinol 126 395-402... [Pg.141]

Shupnik MA (2002) Oestrogen receptor, receptor variants and oestrogen actions in the hypothalamic-pituitary axis. J Neuroendocrinol 14 85-94... [Pg.149]

Precautionary action to reduce the exposure of humans and wildlife to the oestrogenic plastics intermediate bisphenol A looks closer following an EC technical meeting in March. Member States rejected risk assessments put forward by the UK which set aside evidence of low-dose effects on fish and laboratory animals. Bisphenol A is an important plastics intermediate used in polycarbonates and epoxy resins. Global manufacturing capacity stands at two million tonnes per year. [Pg.65]

Clomiphene is a nonsteroidal agent with oestrogenic and anti-oestrogenic properties. The mechanism of action is not precisely clear, but it ultimately leads to the release of the pituitary gonadotropins FSH and LH. It stimulates ovulation in anovulatory or oligo-ovulatory women with adequate endogenous oestrogen activity and an intact hypothalamic-pituitary-ovarian axis. [Pg.403]

Wiseman H. Dietary phytoestrogens, oestrogens and tamoxifen mechanisms of action in modulation of breast cancer risk and in heart disease prevention. In Biomolecular Free Radical Toxicity Causes and Prevention (H Wiseman, P Goldfarb, TJ Ridgway, A Wiseman, editors) John Wiley, Chichester, pp. 170-208, 2000. [Pg.388]

Magee PJ, Rowland IR. Phyto-oestrogens, their mechanism of action current evidence for a role in breast and prostate cancer. Br. J. Nutr. 91, 513-531, 2004. [Pg.390]

Meegan et al. reported the synthesis of a number of [3-lactams and these were evaluated in a series of in vitro assays, which determined their antiproliferative activity in MCF-7 and MDA-MB-231 breast cancer cell lines and also their affinity for the oestrogen receptor (Fig. 6). The cytotoxicity of the [3-lactams was determined in the LDH assay to establish that the antiproliferative effects observed were due to cytostasis rather than cellular necrosis. Most of the compounds demons-treated low cytotoxicity, indicating that their action is cytostatic rather than cytotoxic. Cytotoxicity values considerably below that obtained for tamoxifen (13.4%, 10 pM) were observed with a most potent compound (3%, 10 pM in MCF-7 cell... [Pg.367]

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