The effect of experimental exposure to low doses of zearalenone on uterine histology and morphometry in prepubertal bitches

摘要

The experiment involved 30 clinically healthy prepubertal bitches aged approximately 70 days with an estimated initial body weight (BW) of 8 kg. The animals were randomly divided into two experimental groups (El and EII) and a control group of 10 animals each. Group EI was administered 50 mu g zearalenone (ZEN)/kg BW per as for 42 days, group EII received 75 mu g zearalenone/kg BW per os for 42 days, and the control group was administered placebo per os for 42 days. The bitches were hysterectomized at the end of treatment, and samples of uterine tissue were collected for histological and morphometric analyses. The results of the study indicate that exposure to very low doses of ZEN (100% and 150% of the NOAEL) causes simple glandular hyperplasia of the endometrium accompanied by adenogenesis, angiogenesis, and vasodilatation with the related consequences. The noted changes were more pronounced in group El and less visible in group EII in comparison with group C, which could be indicative of a hormetic dose response