Effects of repeated ochratoxin exposure on renal cells in vitro.
In the present study an in vitro model of subchronic repeated exposure to OTA and OTB was employed to generate ochratoxin-derived subpopulations of human and porcine proximal tubular cells (HKC, IHKE, PKC, LLC-PK1). These cell subpopulations were subsequently used to investigate effects on cell proliferation rates, expression of marker proteins (cytokeratins, vimentin) and the acute cytotoxicity of OTA and OTB (MTT reduction, neutral red uptake, cell number). The hypothesis was tested whether repeated exposure at moderate concentrations of these toxins could provide for a reduced sensitivity of selected cell subpopulations to subsequent toxin exposure. Despite the observed increased cell population doubling times and the reduced sensitivity toward OTA and OTB exposure of some cell types, with the exception of the primary human epithelial cells, no overt changes in the expression of cytokeratin and vimentin could be determined. The presented data, however suggest that repeated exposure of renal epithelial cells to ochratoxins A or B will provide for a subpopulation of cells with reduced ochratoxin-sensitivity and alterations in growth characteristics.
Heussner
A H
AH
Environmental Toxicology, University of Konstanz, P.O. Box X-918, 78457 Konstanz, Germany.
O'Brien
E
E
Dietrich
D R
DR
D000818:Animals; D001706:Biopsy; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004032:Diet; D006801:Humans; D007202:Indicators and Reagents; D007633:Keratins / Q000096:biosynthesis; D007668:Kidney / Q000187:drug effects / Q000473:pathology*; D018374:LLC-PK1 Cells; D008297:Male; D009793:Ochratoxins / Q000633:toxicity*; D012038:Regeneration / Q000502:physiology; D013552:Swine; D014746:Vimentin / Q000096:biosynthesis
D007202:Indicators and Reagents; D009793:Ochratoxins; D014746:Vimentin; C025589:ochratoxin A; D007633:Keratins; C045354:ochratoxin B