title: The Effect of Low Monotonic Doses of Zearalenone on Selected Reproductive Tissues in Pre-Pubertal Female Dogs--A Review.
abstract: The growing interest in toxic substances combined with advancements in biological sciences has shed a new light on the problem of mycotoxins contaminating feeds and foods. An interdisciplinary approach was developed by identifying dose-response relationships in key research concepts, including the low dose theory of estrogen-like compounds, hormesis, NOAEL dose, compensatory response and/or food tolerance, and effects of exposure to undesirable substances. The above considerations increased the researchers' interest in risk evaluation, namely: (i) clinical symptoms associated with long-term, daily exposure to low doses of a toxic compound; and (ii) dysfunctions at cellular or tissue level that do not produce clinical symptoms. Research advancements facilitate the extrapolation of results and promote the use of novel tools for evaluating the risk of exposure, for example exposure to zearalenone in pre-pubertal female dogs. The arguments presented in this paper suggest that low doses of zearalenone in commercial feeds stimulate metabolic processes and increase weight gains. Those processes are accompanied by lower proliferation rates in the ovaries, neoangiogenesis and vasodilation in the ovaries and the uterus, changes in the steroid hormone profile, and changes in the activity of hydroxysteroid dehydrogenases. All of the above changes result from exogenous hyperestrogenizm.
authors.affiliation: Department of Epizootiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13/01, Olsztyn 10-718, Poland. mgaja@uwm.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Gajęcka
authors.affiliation: Department of Veterinary Prevention and Feed Hygiene, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13/29, Olsztyn 10-718, Poland. lukaszz@uwm.edu.pl.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Zielonka
authors.affiliation: Department of Veterinary Prevention and Feed Hygiene, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13/29, Olsztyn 10-718, Poland. gajecki@uwm.edu.pl.
authors.forename: Maciej
authors.initials: M
authors.lastname: Gajęcki
mesh_terms: D000821:Animal Feed; D000818:Animals; D004285:Dogs; D004968:Estrogens, Non-Steroidal / Q000008:administration & dosage*; D005260:Female; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D010053:Ovary / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D011960:Receptors, Estrogen / Q000378:metabolism; D012741:Sexual Maturation; D014599:Uterus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D015025:Zearalenone / Q000008:administration & dosage*
chemical_list: D004968:Estrogens, Non-Steroidal; D011960:Receptors, Estrogen; D015025:Zearalenone
keywords: pre-pubertal female dogs; reproductive system; zearalenone