title: Suppressive effect of zearalenone, an estrogenic mycotoxin, on bovine neutrophil chemiluminescence.
abstract: The effects of zearalenone (ZEA), an estrogenic mycotoxin produced by Fusarium fungi, on bovine neutrophils were investigated in vitro using chemiluninescence, a bactericidal parameter. ZEA suppressed luminol-dependent, phorbol 12-myristate 13-acetate (PMA)-elicited chemiluminescence in a dose-dependent manner at concentrations of 10(-4) M and 10(-5) M. No significant suppression was observed at concentrations lower than 10(-6) M. The possible mode ofaction of 10(-4) M ZEA on the cell activity was investigated with special reference to intracellular Ca2+ ([Ca2+]i) release and estrogen receptors. The 10(-4) M ZEA treatment significantly impaired [Ca2+]i release. When pretreated with a low dose (10(-6) M) of PMA, the cells resisted the ZEA-induced chemiluminescence suppression. However, pretreatment of the cells with the estrogen receptor blockers Tamoxifen and ICl 182,780 (both at 10(-6) M) did not annul the suppressive ZEA action. Considering that PMA is an activator of protein kinase C (PKC), a signal transducing enzyme, and in association with a rise in [Ca2+]i causes cytosolic PKC to shift to the plasma membrane where the activated PKC triggers a varied array of cellular responses, the pharmacological dose of ZEA might have suppressed chemiluminescence by hindering the release of [Ca2+]i and the PKC shift. The results of pretreatment with estrogen receptor blockers, however, did not support the suggestion that the ZEA treatment affected the cells via estrogen receptor pathways.
authors.affiliation: Department of Safety Research, National Institute of Animal Health, Tsukuba, Ibaraki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Murata
authors.forename: N
authors.initials: N
authors.lastname: Shimada
authors.forename: M
authors.initials: M
authors.lastname: Yoshioka
mesh_terms: D000818:Animals; D002118:Calcium / Q000493:pharmacokinetics; D002417:Cattle; D018929:Cell Culture Techniques; D004305:Dose-Response Relationship, Drug; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D005260:Female; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D011960:Receptors, Estrogen / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction; D015025:Zearalenone / Q000494:pharmacology*
chemical_list: D004968:Estrogens, Non-Steroidal; D011960:Receptors, Estrogen; D015025:Zearalenone; D002118:Calcium