title: Non-classical mechanisms of steroid sensing in the ovary: lessons from the bovine oxytocin model.
abstract: Steroidogenic tissues such as the ovary, testes or adrenal glands are paradoxical in that they often indicate actions of steroid hormones within a dynamic range of ligand concentration in a high nanomolar or even micromolar level, i.e. at the natural concentrations existing within those organs. Yet ligand-activated nuclear steroid receptors act classically by direct interaction with DNA in the picomolar or low nanomolar range. Moreover, global genomic studies suggest that less than 40% of steroid-regulated genes involve classical responsive elements in gene promoter regions. The bovine oxytocin gene is a key element in the maternal recognition of pregnancy in ruminants and is regulated via an SF1 site in its proximal promoter. This gene is also regulated by steroids acting in a non-classical manner, involving nuclear receptors which do not interact directly with DNA. Dose-response relationships for these actions are in the high nanomolar range. Similar 'steroid sensing' mechanisms may prevail for other SF1-regulated genes and predict alternative pathways by which environmental endocrine disruptors might influence the functioning of steroid-producing organs and hence indirectly the steroid-dependent control of physiology and development.
authors: Leibniz Institute for Farm Animal Biology, 18196 Dummerstorf, Germany; School of Molecular and Biomedical Science, University of Adelaide, SA 5005, Australia.
authors: Richard
authors: R
authors: Ivell
authors: Leibniz Institute for Farm Animal Biology, 18196 Dummerstorf, Germany.
authors: Yanzhenzi
authors: Y
authors: Dai
authors: School of Molecular and Biomedical Science, University of Adelaide, SA 5005, Australia.
authors: Navdeep
authors: N
authors: Mann
authors: Leibniz Institute for Farm Animal Biology, 18196 Dummerstorf, Germany. Electronic address: anand-ivell@fbn-dummerstorf.de.
authors: Ravinder
authors: R
authors: Anand-Ivell
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D006801:Humans; D008954:Models, Biological; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D010121:Oxytocin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013256:Steroids / Q000378:metabolism*; D015262:Xenobiotics / Q000494:pharmacology
chemical_list: D013256:Steroids; D015262:Xenobiotics; D010121:Oxytocin
keywords: Bovine ovary; Estrogen receptor-alpha; Estrogen receptor-beta; Non-classical steroid signaling; Oxytocin; Oxytocin receptor