Sister chromatid exchange frequency in cultured isolated porcine urinary bladder epithelial cells (PUBEC) treated with ochratoxin A and alpha.
The mycotoxin ochratoxin A (OTA) and its metabolite ochratoxin alpha (OT-alpha) were investigated, to examine their potency to induce sister chromatid exchanges (SCE) in cultured porcine urinary bladder epithelial cells (PUBEC) (primary culture). Serum-free cultured PUBEC were incubated for 5 h with either OTA or OT-alpha, respectively, and subsequently cultured in the presence of 5-bromo-2-deoxyuridine (BrdU). After two cell cycles, mitosis was inhibited by the colchicine derivative Colcemid, cells were fixed and chromosomes were prepared for SCE analysis. For OTA, a dose-dependent increase in SCE frequency was measured in concentrations between 100 pM and 100 nM OTA. At 100 nM OTA, SCE frequency increased by about 41%, compared to the base SCE level (7.27 SCEs per chromosome set, solvent control). Higher concentrations of OTA were cytotoxic. The metabolite OT-alpha also increased SCE frequency, but at higher concentrations. At a concentration of 10 microM OT-alpha, an increase of about 55% was detected. OT-alpha showed no cytotoxic effect. These results indicate that OTA is genotoxic in this in vitro system, which represents the urinary bladder epithelium, a target organ of OTA in vivo. It could also be shown that OT-alpha, which is said to be non-toxic, is genotoxic in this assay at higher concentrations.
Föllmann
W
W
Institut für Arbeitsphysiologie, Universität Dortmund, Germany.
Hillebrand
I E
IE
Creppy
E E
EE
Bolt
H M
HM
D000818:Animals; D002478:Cells, Cultured; D004848:Epithelium / Q000187:drug effects; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D009793:Ochratoxins / Q000633:toxicity*; D012854:Sister Chromatid Exchange / Q000235:genetics*; D013552:Swine; D001743:Urinary Bladder / Q000187:drug effects*
D009153:Mutagens; D009793:Ochratoxins; C000426:5-chloro-8-hydroxy-3,4-dihydro-3-methylisocoumarin-7-carboxylic acid; C025589:ochratoxin A