The toxic effects and fate of intravenously administered zearalenone in goats.
To clarify the toxic effects and fate of zearalenone (ZEA) in ruminants, we studied histopathological changes and toxicokinetic profiles in goats administered with a single intravenous (iv) injection of ZEA at doses of 2.4 mg/kg bw and 1.2 mg/kg bw, respectively. The expression of the mRNA of estrogen receptor (ER) alpha and beta in tissues was also investigated. The histopathological study revealed that ZEA caused hepatocellular swelling and lymphocytic infiltration in the liver, kidney, and uterus. The expression of ERalpha mRNA was enhanced by ZEA in association with the histopathological changes, indicating the possible involvement of ERalpha in the toxic effects of ZEA. For toxicokinetic profiles, blood plasma, urine, and feces were collected consecutively after iv injection of ZEA and analyzed for ZEA and its metabolites with high performance liquid chromatography (HPLC). alpha-Zearalenol (ZOL) and beta-ZOL were detected with ZEA, but alpha-zearalanol (ZAL), beta-ZAL, and zearalanone were below the detection limits. The distribution half-life (t(1/2alpha)) and elimination half-life (t(1/2beta)) of ZEA were 3.15 and 28.58h, respectively. ZEA, alpha-ZOL, and beta-ZOL were excreted in urine and feces, with beta-ZOL being the predominant metabolite. The ZEA and ZOL in urine were largely in their glucuronide and/or sulphate conjugated forms, while those in feces were largely in their free forms. This study showed the toxic effect of zearalenone and its metabolites, and their pharmacokinetic characteristics in goats.