Carry-Over Factor of Zearalenone in the Roof of the Third Ventricle of the Brain and Selected Skeletal Muscles During Low-Dose Zearalenone Mycotoxicosis in Prepubertal Gilts

The aim of this study was to determine whether exposure to low doses of zearalenone (ZEN) over a period of six weeks affects the values of the carry-over factor (COF) of ZEN in the roof of the third cerebral ventricle (RTCV) and in selected skeletal muscles (longissimus and quadriceps) in prepubertal gilts. The study was conducted on 60 clinically healthy prepubertal gilts with an initial body weight (BW) of 14.5 ± 2 kg. Gilts were randomly assigned to a control group (group C; n = 15) and three experimental groups (ZEN5, ZEN10, and ZEN15; n = 15 each). Groups ZEN5, ZEN10, and ZEN15 were administered ZEN per os at doses of 5 µg/kg BW, 10 µg/kg BW, and 15 µg/kg BW, respectively. Group C animals were orally administered a placebo. Tissue samples (brain and skeletal muscles) were collected post-mortem for toxicological analyses on exposure days 7 (D1), 21 (D2), and 42 (D3). The concentrations of ZEN and its metabolites, α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), were determined in the collected samples. All examined tissues contained the parent compound, but ZEN metabolites were not detected in any of the samples. The absence of ZEN metabolites may have resulted from a physiological deficit of estradiol (E2) and, consequently, testosterone (T) and progesterone (P4) in prepubertal gilts. Low-dose ZEN mycotoxicosis led to a persistent presence of ZEN in the RTCV (COF from 1·10−6 on D1 to 7·10−7 on D3) and somewhat lower ZEN levels in skeletal muscles (COF from 8·10−6 on D1 to 6·10−7 on D3). The presence of ZEN in the RTCV confirms that it crosses the blood–brain barrier and may therefore participate in the hormonal homeostasis of the brain.