Growth and Endocrine Responses of Lambs to Zeranol Implants: Effects of Preimplant Growth Rate and Breed of Sire

Wiggins, J. P.; Rothenbacher, H; Wilson, L. L.; Martin, Roy J.; Wangsness, P. J.; Ziegler, J. H.

doi:10.2527/jas1979.492291x

Cited by 29 publications

(17 citation statements)

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“…It is present as a contaminant in stored cereals, being found in barley, corn, corn flakes, rice and wheat at concentrations from 35 to 115 µg kg -1 (Hagler et al, 1984;Schoental, 1985;Luo et al, 1990). Zearalenone also is used as an anabolic agent to enhance growth in cattle and lambs (Ralston, 1978;Wiggins et al, 1979). In contrast to genistein, pharmacological doses (10 mg kg -1 body weight) of zearalenone have been associated with an increased breast cancer risk in rats (Schoental, 1974).…”

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Prepubertal exposure to zearalenone or genistein reduces mammary tumorigenesis

et al. 1999

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Prepubertal exposure to a pharmacological dose (500 mg kg −1 ) of the phyto-oestrogen genistein can reduce the incidence and multiplicity of carcinogen-induced mammary tumours in rats. However, such an exposure also disrupts the function of the hypothalamic–pituitary–gonadal axis, making it unsuitable for breast cancer prevention. We studied whether prepubertal exposure to genistein at a total body dose broadly comparable to the level typical of Oriental countries, approximately 1 mg kg −1 body weight, affects mammary tumorigenesis. We also studied whether prepubertal exposure to zearalenone, a major source for phyto-oestrogens in the USA, influences breast cancer risk. Prepubertal rats were treated between postnatal days 7 and 20, with 20 μg (~ 1 mg kg −1 body weight) of either genistein or zearalenone. Zearalenone exposure significantly reduced both the incidence and multiplicity of mammary tumours induced by 7,12-dimethylbenz(a)anthracene (DMBA). Genistein exposure significantly reduced tumour multiplicity, but not tumour incidence, when compared with vehicle-treated animals. Furthermore, 60% of the tumours in the genistein group were not malignant, while all the tumours analysed for histopathology in the vehicle and zearalenone groups were adenocarcinomas. A higher number of differentiated alveolar buds, and lower number of terminal ducts, were present in the DMBA-treated mammary glands of the phyto-oestrogen exposed rats. The concentration of oestrogen receptor (ER) binding sites after the DMBA treatment was low in the mammary glands of all groups but a significantly higher proportion of the glands in the zearalenone exposed rats were ER-positive (i.e. ER levels ≥ 5 fmol mg −1 protein) than the glands of the vehicle controls. Our data suggest that a prepubertal exposure to a low dose of either zearalenone or genistein may protect the mammary gland from carcinogen-induced malignant transformation, possibly by increasing differentiation of the mammary epithelial tree. © 1999 Cancer Research Campaign

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confidence: 99%

Prepubertal exposure to zearalenone or genistein reduces mammary tumorigenesis

et al. 1999

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“…Ces effets peuvent être dus, soit à la réduction de la dégradation de la T4, soit à la diminution de la capacité de fixation de la TBG (thyroxine binding, globulin) plasmatique par les oestrogènes, soit enfin à l'accroissement de poids de la thyroïde. L'augmentation de la T4 est rarement accompagnée d'une modification de la T3 (Gopinath et Kitts, 1984b) (Williams et al, 1991) ou de l'activité de la thyroïde (Wiggins et al, 1979). Enfin, certains essais ne montrent aucune modification de la T3 ou de la T4 4 circulante (Rhind et al, 1984 ;Hunter et Vercoe, 1987 ;Galbraith et al, 1988).…”

Section: Rôles Des Androgènes Et Des Associations Cestrogèneslandrogènesunclassified

Revue bibliographique quantitative sur l'utilisation des hormones anabolisantes à action stéroïdienne chez les ruminants en production de viande. Il. Principaux modes d'action

Schmidely¹

1993

Reprod. Nutr. Dev.

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“…Its natural occurrence in corn, wheat, and barley has been documented (Mirocha et al 1977(Mirocha et al , 1981. Consumption of foods and feeds polluted by zearalenone-producing fungi, such as F. roseum "graminearum" and some isolates of F. tricincturn, F. oxysporum, and F. moniliforrne, gives rise to several reproductive disorders such as infertility in pigs (Chang et al 1979) as well as enhanced growth and inOffprint requests to: P. R. Walln6fer creased testicular weights in cattle and lambs (Ralston 1978;Wiggins et al 1979). Although it is known that zearalenone competes with 17-fl-estradiol for binding to the uterine cytosol receptors (Kiang et al 1978, Boyd andWitliff 1978) and interferes with steroid-metabolizing enzymes (Kiessling and Pettersson 1978; Thouvenot and Morfin 1980;Olsen et al 1981) its exact toxicological properties are still unclear.…”

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confidence: 99%

Formation of [13C]- and [14C]zearalenone by Fusarium graminearum DSM 4529

Zill

Engelhardt

Wohner

et al. 1989

Appl Microbiol Biotechnol

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To raise the yields for the production of 14C-labelled zearalenone in Fusarium cultures the influence of growth conditions and known effectors or precursors of toxin biosynthesis was studied. Benzoic acid and 2,4-dihydroxybenzoic acid used as precursors decreased toxin formation; in the presence of different pesticides such as 2,4-dichlorophenoxyacetic acid, however, toxin production increased up to 140%. The known pathway of zearalenone biosynthesis could be confirmed from the relative extents of 13C-incorporation into the zearalenone molecule by incubating Fusarium 9raminearum DSM 4529 with D-(+)-[1-~3C]glucose as carbon source. When grown in the presence of D-[U-14C]glucose or [2-~4C]malonic acid the strain produced [14C]zearalenone with specific activities of 0.07 and 0.09 ~tCi/mg, the ~4C-incorporation rates being 0.34% and 0.48%, respectively.

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Growth and Endocrine Responses of Lambs to Zeranol Implants: Effects of Preimplant Growth Rate and Breed of Sire

Cited by 29 publications

References 0 publications

Prepubertal exposure to zearalenone or genistein reduces mammary tumorigenesis

Prepubertal exposure to zearalenone or genistein reduces mammary tumorigenesis

Revue bibliographique quantitative sur l'utilisation des hormones anabolisantes à action stéroïdienne chez les ruminants en production de viande. Il. Principaux modes d'action

Formation of [13C]- and [14C]zearalenone by Fusarium graminearum DSM 4529

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