The effect of experimental, long-term exposure to low-dose zearalenone mycotoxicosis on the histological condition of ovaries in sexually immature gilts.

Farm animals are at risk of exposure to zearalenone (ZEA) in feedstuffs, which may lead to aberrations in their reproductive development, thereby adversely affecting production outcomes. The objective of this study was to determine the effect of long-term (48 days), per os administration of low ZEA doses (50% [20 µg ZEA/kg body weight (bw)] and 100% [40 µg ZEA/kg bw] NOAEL values) on anatomopathological changes in the ovaries of sexually immature gilts. The experiment involved 12 clinically healthy gilts aged 2 months with an initial body weight of about 40 kg and a determined immune status. The animals were randomly divided into two experimental groups (E1, E2) and a control group (C; all n = 4). Group E1 received per os 20 µg ZEA/kg bw for 48 days; group E2 received per os 40 µg ZEA/kg bw for 48 days; and group C received per os placebo for 48 days. Analytical samples of the mycotoxin were administered daily per os in gelatine capsules before morning feeding. Animals were sacrificed at the end of the experiment. The results of anatomopathological examinations of the ovaries in immature gilts subjected to long-term, low-dose ZEA exposure showed that ZEA-induced experimental hyperoestrogenism lowered the proliferative ability of granulosa cells of the ovarian follicle walls and of the connective tissue of the ovarian stroma, in particular at the lower ZEA dose.

The impact of zearalenone on the level of the selected estrogens in blood serum of sexually immature gilts.

The aim of the study was to evaluate the influence of low dose (LOEL - lowest observed effect level) of zearalenone (200 microg/kg b.w.), applied per os for 7 days (short-term intoxication), on sexual behavior, concentration of the examined xenobiotic and its metabolite and selected estrogens in sexually immature gilts: ovariohysterectomised (group D1) and intact (group D2) animals. Clinical signs of oestrus (reddening, oedema and hyperaemia of the vulva and serorhoea from the reproductive tract--lack of standing reflex) were obserwed in group D1 on day 6 and in group D2 on day 4 of the experiment. Laboratory analyses of blood plasma were carried out determine the presence of zearalenone and alpha-zearalenole. They revealed an increase in the level of alpha-zearalenol before the oestrus, decrease in total amount of both examined substances on day when the oestrus appeared and increase in the level of both examined xenobiotics in the post oestrus period together with the higher share of zearalenone. Medium concentrations of estrone and estradiol within the borders of method determination in the majority of periods examined. Higher levels of estrone (32.0 pg/ml) were found on day 4, in the group D2 and estradiol (6.5 pg/ml) on day 6 in the D2 group. The presents study revealed that zearalenone applied per os at LOEL dose causes the incidence of apparent sexual readiness (without standing reflex) in sexually immature gilts with the somatically immature reproductive system.

Level of zearalenone in blood serum and lesions in ovarian follicles of sexually immature gilts in the course of zearalenone micotoxicosis.

The aim of the study was to determine how a low dose of zearalenone applied orally for eight days influences the level of zearalenone (ZEN) and alpha-zearalenole in blood plasma and causes the occurrence of histopathological changes in the cells of the ovarian follicles in sexually immature gilts. The animals were divided into 2 groups (control, C; n = 4 and experimental, E; n = 4). The gilts from group E were treated daily with zearalenone at a dose of 200 microg/kg b.w. The level of zearalenone and alpha-zearalenole (ZON as the sum of the levels of both zearalenone and alpha-zearalenole) was measured daily. On day eight of the experiment the animals were sacrificed and their ovaries were taken for histopathological examination. The tissue sections obtained were HE- and PAS-stained according to McManus. The presence of PCNA antigen was also estimated. The highest concentration of ZON was noted on day 5 in group E (8.16 +/- 2.49 ng/ml). External estrus symptoms without standing reflex were observed in group E on day 4. In group C there were no pathological changes in the ovaries. In group E, a few ovarian follicles were found, but they were located in the cortical layer. They were filled with a liquid substance rich in protein and without the granulosa layer. There was disintegration with apoptotic-like changes of the PCNA-negative cells in the granulosa layer of single mature follicles. On day 4 the dose of zearalenone caused disturbances in the process of development and maturation of some of the best developed ovarian follicles. This probably occurred through the activation of on apoptosis-like process of the granulosa cells with simultaneous manifestation of estrus without standing reflex.

Metabolic profile of pigs fed feed containing zearalenone destructor.

Zearalenone (ZEA) is a member of macrocyclic lactons family. It is a toxin--phytosteride produced by fungi of Fusarium ssp. genus. Zearalenone contaminates food and animal feeding stuffs and its destruction is difficult. It requires application of particular compounds that would bind zearalenone in the feed or feeding stuff or in the gastrointestinal tract and decrease its bio-accessibility. It should also fulfil all the safety requirements regarding the plant supplements and animals that are fed with this feed. The aim of the study was to estimate if the feed supplemented with different doses of zearalenone and zearalenone destructor causes changes of the metabolic profile in gilts. The results obtained show that applied destructor did not cause negative haematological and biochemical changes in the blood of the gilts examined. It can be suggested that it is a safe feed supplement pigs in prevention of zearalenone micotoxicosis.

Preliminary results of monitoring research on zearalenone presence in blood of women with neoplastic lesions in reproductive system.

The aim of the monitoring of zearalenone presence in the blood plasma of women with neoplastic lesions in the reproductive tract was to asses whether the phytosteride is noted in the patients blood and whether the correlation exists between its presence and the incidence of particular neoplasm. The presence of zearalenone or its metabolite--alpha-zearalenole, was noted in 13.51% of the examined women. In 60% of the patients with the confirmed presence of the xenobiotic it was noted in the lowest concentrations. These patients had neoplastic lesions of Carcinoma corpus uteri type.

Zearalenone applied per os provides adverse effects in structure of chosen parts of bitch reproductive system.

Both earlier investigations and complete formulas of pet food for dogs show that professionally prepared pet food is based in 30% on the material of the plant origin. Our own investigations prove that animal feeding stuffs of the plant origin are very often vectors of many undesirable substances (including micotoxins) that are unfavourable for carnivores. Zearalenone is a micotoxin, which frequently occurs among them. It was revealed in pet food in quantities from 5.0-299.5 microg/kg. It is a very dangerous xenobiotic because of its quick and easy absorption in the organism after per os application in monogastric animals. It is also a sterid and despite its plant origin it binds estrogen receptors in the reproductive tract and causes its hypo- and dysfunction. It is clearly visible in young, growing organisms and those during the menopause. In bitches, dysfunctions of the reproduction system, such as: endometritis-pyometra syndrome, prolonged oestrus, ovarian cysts and others are often found. It is supposed that specific for this species hormonal regulation of the reproduction processes based on the long progesterone and prolactin cycles, and on high sensibility to estrogens plays an important role in the etiopathogenesis of these dysfunctions. The application of hormones in bitches in therapeutic and biotechnical (contraception) purposes are the other factors, which should be taken into account in this aspect. There are some suggestions that therapeutic management, unfortunately connected with mistakes in the medical art, is often a cause of pathological condition in a reproductive organ in bitches. However, another reason of these disorders may be that bitches take zearalenone with the commercial pet food. The long-lasting intake of the feed with a low dose of this micotoxin may be the factor, which complicates hormonal regulation of the reproduction processes and is the cause of many disorders. Our own pilotage investigations showed that application of zearalenone at a dose of 200 microg/kg b.w. for 7 days leads to apoptotic-like changes in granule cells in the bitch reproductive system, atresia of follicular cells and oedema and hyperplasia of the oviductal and uterine cells. They could also indicate a follicular phase of the oestrus cycle in bitch. However, it did not take place.

The occurrence of zearalenone and its derivatives in standard and therapeutic feeds for companion animals.

Weather anomalies are the cause of the more and more frequent occurrence of the rezorcycyklic acid derivatives--zearalenone--in the fodders of the animal origin. This mycotoxine induces in the organism of gilts an oestrus-like condition. According to the latest reports the zearalenone derivatives were found in the human food-stuffs in the retail market. It was considered important to assay the concentration of zearalenone and its derivatives in the standard and therapeutic feeds for dogs. Zearalenone and its derivatives were found in 48 commercial formulations for a total number of 57 brands analysed.

Influence of low doses of deoxynivalenol applied per os on chosen indexes of immune response in swine.

Deoxynivalenole is one of the more often present micotoxins in home produced feeds. The immunosuppressive action of this xenobiotic on the animal organism plays an important role among other symptoms of intoxication when high doses of this micotoxin are applied. However, low doses are likely to activate some adaptive mechanisms of the immune system, a fact confirmed in the present investigations.

Influence of zearalenone on reproductive system cell proliferation in gilts.

Zearalenone (ZEA) is a macrocyclic lactone, estrogenic, diet-depending and fusaric micotoxin, which is produced on many kinds of cereals and feeds in the favourable conditions of humidity and temperature. The structure of ZEA is similar to the structure of estrogens and it enables binding to the estrogenic receptors. The stimulation of protein synthesis in the cells of the reproductive system, which causes intensification of cell proliferation, is one of the effects of ZEA actions. Oedema and vulva reddening are the clinical, external signs of ZEA intoxication in pigs. The aim of this study was to designate the degree of reproductive cell proliferation after low doses of ZEA were applied per os in sexually immature gilts with simultaneous monitoring of zearalenone and alpha-zearalenol levels in peripheral blood. The following were observed in the gilts examined fluctuations of zearalenone and alpha-zearalenol levels in blood, which were connected with entero-hepatic circulation and also numerous histopathological changes in ovarian follicle structure. These changes were present in the reproductive system of sexually immature gilts with a big contribution of PCNA-positive cells. The studies show that zearalenone application in sexually immature gilts caused ovarian follicle atresia and apoptoso-like changes in granule cells. Intensified cell proliferation, which was expressed with the growth of PCNA index, was observed in uterus and oviduct.