The Effect of Different Doses of Zearalenone in Feed on the Bioavailability of Zearalenone and Alpha-Zearalenol, and the Concentrations of Estradiol and Testosterone in the Peripheral Blood of Pre-Pubertal Gilts (original) (raw)
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Theriogenology, 1987
Ninety-nine sexually mature, non-pregnant gilts were checked for estrus daily with a mature boar and then allocated at estrus (D 0) to receive 2 kg/d of a diet containing 0, 1, 5 or 10 ppm purified zearalenone between D 5 and 20 of the estrous cycle during two seasons of the year (winter and summer). None of the gilts exhibited any visual signs of "hyperestrogenism" and there was no effect of season on interestrous interval (P > 0.05). A significant effect of zearalenone dose on inter-estrous interval was detected (P < 0.001). Gilts receiving 0 or 1 ppm had similar inter-estrous intervals (21.0 + 0.3 and 21.5 2 0.8 d, respectively) whereas gilts receiving 5 and 10 ppm had extended cycles (29.2 + 2.9 and 32.7 + 3.3 d, respectively). Plasma progesterone concentrations at D 19 to 21 were higher in gilts with extended cycles (P ,< 0.001) and corpora lutea (CL) were present at laparotomy. Some 86% of these retained CL underwent spontaneous regression resulting in the onset of estrus within the next 30 d. Fecal zearalenone concentrations rose during ingestion of contaminated diets and declined to pretreatment values within 2 d (1 ppm) to 8 d (10 ppm) of the cessation of treatment. These data show that feeding zearalenone at concentrations of 5 to 10 ppm from D 5 to 20 of the estrous cycle causes luteal mai.ntenance and extended inter-estrous intervals. Spontaneous regression of these CL usually occurs within 30 d after zearalenone is removed from the diet. Fecal zearalenone analysis does not appear to be an effective method for determining prior exposure to zearalenone when carried out more than a lew days following the last ingestion of zearalenone.
Factors determining sensitivity of prepubertal gilts to hormonal influence of zearalenone
Polish journal of veterinary sciences, 2009
Among large husbandry animals, swine are the most predisposed to zearalenone (ZEA) intoxication, mainly because cereal is an important component of their diet. Studies performed so far (in vivo, in vitro) suggest that ZEA and its metabolites, which may appear due to ZEA biotransformation (especially alpha-zearalenole; alpha-ZOL), can modify signaling cascades of endogenous sex steroids, through either receptor or non-receptor mechanisms. Of all age groups of swine, immature gilts are particularly predisposed to zearalenone intoxication, as manifested by the occurrence of genital tract tissue dysfunction on exposure to ZEA. The intensity of the adverse effects observed at either systemic or local level in gilts, when compared to sexually mature swine females, suggest that specific age-dependent physiological conditions may exist, which determine the high sensitivity of gilts to exogenous estrogen-like compounds, including ZEA.
Toxins
Zearalenone (ZEN) is a mycotoxin that not only binds to estrogen receptors, but also interacts with steroidogenic enzymes and acts as an endocrine disruptor. The aim of this study was to verify the hypothesis that low doses, minimal anticipated biological effect level (MABEL), no-observed-adverse-effect level (NOAEL) and lowest-adverse-effect level (LOAEL), of ZEN administered orally for 42 days can induce changes in the peripheral blood concentrations of selected steroid hormones (estradiol, progesterone and testosterone) in pre-pubertal gilts. The experiment was performed on 60 clinically healthy gilts with average BW of 14.5 ± 2 kg, divided into three experimental groups and a control group. Group ZEN5 animals were orally administered ZEN at 5 μg ZEN/kg BW, group ZEN10 — at 10 μg ZEN/kg BW, group ZEN15 — at 15 μg ZEN/kg BW, whereas group C received a placebo. Five gilts from every group were euthanized on analytical dates 1, 2 and 3 (days 7, 14 and 42 of the experiment). Qualitat...
Experimental and Toxicologic Pathology, 2012
The objective of this study was to determine the effect of long-term (48 d), per os animal administration of low zearalenone (ZEA) doses (50% and 100% NOAEL values) on the dynamics of changes in the morphometric parameters of the reproductive organs in sexually-immature gilts. The experiment involved 12 clinically-healthy gilts aged 2 months with initial body weight of ± 40 kg and a determined immune status. The animals were randomly divided into two experimental groups (E1, n=4; E2, n=4) and a control group (C, n=4). Group E1 was administered per os 20 µg of ZEA/kg b.w. for 48 d, group E2 received per os 40 µg of ZEA/kg b.w. for 48 d, and group C was administered per os placebo for 48 d. The mycotoxin was administered daily per os animal in gelatin capsules before morning feeding. The animals were slaughtered at the end of the experiment. No significant morphometric changes were noted in the reproductive system of the gilts, except for an increase in the number of medium-sized ovarian follicles in group E1. This suggests that ZEA at low concentrations may cause hormonal effects (hyperoestrogenism) but it does not exhibit xenobiotic activity.
Journal of Animal Science
Effects of estradiol benzoate (EB) and zearalenone (Z) on luteal maintenance and plasma hormone concentrations were studied in 45 gilts. Gilts were allocated to receive either 20 mg Z, 2 mg EB or no treatment (C) on d 1 to 5 (T1), 6 to 10 (T2) or 11 to 15 (T3) of an estrous cycle (five per treatment). Onset of estrus was designated as d 0 of the estrous cycle. Zearalenone was added to the daily ration and EB was administered via an intramuscular injection. Blood samples were collected every 10 min over a 4-h period on the first 2 d prior to onset of treatment; the first, third and fifth days of treatment; and the first two and the fifth day after the end of the treatment periods. Gilts receiving EB and Z during T2 and T3 had longer (P<.05) inter-estrous intervals than C gilts. The range in inter-estrous intervals for Z and EB treatments was 28 to 74 and 27 to 63 d, respectively. Mean plasma progesterone concentrations were elevated (P<.05) during T2 and T3 in EB and Z-treated gilts when compared with C females. Estradiol benzoate treatment during T2 and T3 reduced (P<.05) mean plasma luteinizing hormone (LH) concentrations more than C or Z treatments. Mean plasma concentrations of 13, 14-dihydro-, 15-keto-prostaglandin F~ ~ (PGFM) during T3 were higher (P<.05) in C and Z gilts on d 13 and 15 post-estrus when compared with EB gilts. These results indicated that 2 mg EB or 20 mg Z from d 6 to 10 or 11 to 15 of the estrous cycle extended the inter-estrous interval in swine. Estradiol benzoate during the same periods decreased mean plasma LH concentrations while Z did not. Additionally, EB treatment during T3 prevented the increase in PGFM concentrations of d 13 and 15 observed in both C and Z guts.
Effects of zearalenone in prepubertal gilts
Pesquisa Veterinária Brasileira, 2011
Prepubertal gilts were fed with a diet containing zearalenone (ZEA) in a concentration of 0.75 mg/kg for 21 days. The effects of this mycotoxin on morphologic aspects of the reproductive tract as well as on complete blood count (CBC), serum biochemistry analysis (SBA) and humoral immune response against sheep red blood cells (SRBC) were evaluated. There was a significant increase (P<0.05) on the reproductive tract weight, vulvar area, height of the epithelial cells of endometrial glands and uterine mucosa. These results showed the ability of this nonsteroidal mycotoxin in mimicking actions of 17β estradiol at the concentration of 0.75mg/kg. No changes in weight gain, CBC, SBA parameters and humoral response against SRBC were observed.
Estrogenic and Non-Estrogenic Disruptor Effect of Zearalenone on Male Reproduction: A Review
International Journal of Molecular Sciences
According to some estimates, at least 70% of feedstuffs and finished feeds are contaminated with one or more mycotoxins and, due to its significant prevalence, both animals and humans are highly likely to be exposed to these toxins. In addition to health risks, they also cause economic issues. From a healthcare point of view, zearalenone (ZEA) and its derivatives have been shown to exert many negative effects. Specifically, ZEA has hepatotoxicity, immunotoxicity, genotoxicity, carcinogenicity, intestinal toxicity, reproductive toxicity and endocrine disruption effects. Of these effects, male reproductive deterioration and processes that lead to this have been reviewed in this study. Papers are reviewed that demonstrate estrogenic effects of ZEA due to its analogy to estradiol and how these effects may influence male reproductive cells such as spermatozoa, Sertoli cells and Leydig cells. Data that employ epigenetic effects of ZEA are also discussed. We discuss literature data demonst...
Molecules, 2015
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.
Journal of Applied Animal Research, 2016
The present study was conducted to determine the toxic dose response of a chronic dietary Zearalenone (ZEA) in weaned young rats. Sixty, 21-day-old, Sprague Dawley female rats were randomly allocated to five groups of four replicate cages containing three rats. Rats were fed diets with increasing amounts of ZEA (0, 0.5, 0.9, 1.8 and 3.6 mg/kg) for 4 weeks. Daily feed intake was reduced (P < .05) by feeding the ZEA diets with 0.9 and 3.6 mg ZEA/kg feed. Rats fed the diet containing 1.8 mg ZEA/kg increased (P < .05) the body weight gain (BWG) and reduced (P < .05) feed conversion rate (FCR) as compared to the control group. The two highest levels of dietary ZEA also increased (P < .05) the weight of the uterus. However, ovaries' weight, timing of vaginal opening and the inter-oestrous interval were not affected by increasing the doses of dietary ZEA (P > .05). Similarly, serum concentrations of total protein, follicle-stimulating hormone and alanine aminotransferase, aspartate aminotransferase and alkaline phosphate activities were not altered by the ZEA treatments. In conclusion, our results indicated that a chronic dietary consumption of ZEA at concentrations of 1.8 mg ZEA/kg increases the BWG and the uterus weight of weaning female rats.
The Influence of Zearalenone on Selected Hemostatic Parameters in Sexually Immature Gilts
Toxins
Vascular toxicity induced by xenobiotics is associated with dysfunctions or damage to endothelial cells, changes in vascular permeability or dysregulation of the vascular redox state. The aim of this study was to determine whether per os administration of zearalenone (ZEN) influences selected hemostatic parameters in prepubertal gilts. This study was performed on female gilts divided into a control group which received placebo and an experimental group which received ZEN at a dose of 5.0 µg·kg−1 b.w. × day−1. On days 14, 28 and 42, blood samples were collected from the animals for analyses of hematological, coagulation and fibrinolysis parameters, nitric oxide, von Willebrand factor antigen content and catalase activity. The results demonstrated that the treatment of gilts with ZEN at a dose below no observable adverse effect level did not affect the primary hemostasis and the blood coagulation cascade. However, ZEN could have temporarily affected the selected indicators of endothel...