EN
Companion animals, including bitches, are exposed to intoxication with zearalenone (ZEN) present in feed, and the above may lead to reproductive disorders which are often noted in veterinary practice. The aim of this study was to determine the effect of long-term and low-dose ZEN intoxication on the immunoexpression (optical density) of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and 17ß-hydroxysteroid dehydrogenase (17ß-HSD) in the ovaries of pre-pubertal bitches. The experiment involved 30 clinically healthy, immature Beagle bitches aged approximately 70 days with initial average body weight of 8 kg. The animals were randomly divided into two experimental groups (EI and Ell) and a control group (C; n=10 in all groups). Group EI was administered 50 |ig ZEN/kg BWper os over a period of 42 days, group Ell received 75 |ig ZEN/kg BW per os for 42 days, and group C was administered placebo per os over a period of 42 days. Weighed amounts of the analyzed mycotoxin were administered every morning in gel capsules before feeding. The animals were subjected to ovariohysterectomy at the end of the experiment. Immunocytochemical analyses were performed to localize 3ß-HSD and 17ß-HSD enzymes and determine their optical density. The results revealed that changes in the immunoexpression of the above enzymes were inversely proportional to the applied dose of ZEN substrate.