A cell culture model of isolated porcine urinary bladder epithelial cells for genotoxicity studies.
Monolayer cultures of porcine urinary bladder epithelial cells were obtained by isolating cells from bladders of freshly slaughtered pigs. The cultures were investigated morphologically and characterized according to their growth characteristics and enzymatic functions. Ultrastructural investigations demonstrated that the cells regain their in vivo polarization with apically situated membrane vesicles, tight junctions and desmosomes between neighbouring cells when they have built up a confluent monolayer. Membrane integrity and high cell viability was indicated by low levels of lactate dehydrogenase activity released into the medium. The chromosome set of the cells was stable during the first 5 wk of culture. Under standard culture conditions activities of the enzymes alkaline phosphatase and acid phosphatase were stable over a period of 4 wk. gamma-glutamyl transpeptidase activity, indicating a dedifferentiation process, did not increase. Activity of NADH-dehydrogenase dropped, indicating a decrease in ER as a consequence of adaptation to the culture conditions. By measuring concentration dependent increase of sister chromatid exchanges (SCEs) induced by N-methyl-N'-nitro-N-nitrosoguanidine and 2-acetylaminofluorine, the suitability of this model for genotoxicity tests was estimated. These results indicate that the model can be used as a target for bladder cancer inducing agents to investigate the effects of such agents on the level of the target organ in further genotoxicity studies.
Föllmann
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Institut für Arbeitsphysiologie an der Universität Dortmund, Ardeystrasse 67, 44139 Dortmund, Germany.
Guhe
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