Freshly dissected livers from 12 days-old chicken embryo were prepared for primary culture. After trypsinizing, the cells were grown as monolayers in bottle culture on glass coverslips at 37°C using Eagle's minimal essential medium supplememted with 5 percent calf serum, 100 units/ml penicillin, and 100μg/ml streptomycin.
In the presence of aflatoxins the characteristic cytological change was a marked quantitative decrease of the liver parenchymal cell nucleoli. The mesenchymal cells, on the other hand, were less sensitive to the toxic agents.
It has been pointed out that the characteristics of enzyme inhibition by aflatoxins resemble those by actinomycin D. The culture cells treated with actinomycin D revealed that the mesenchymal cell nucleoli can scarecely be recognized and, on the other hand, there are distinct nucleoli in the parenchymal cells.
Some specimens which had been identified as aflatoxin B
1 with either physical or chemical methods were tested by this “New bioassay method”. The characteritic nycleoli changes were observed in the parenchymal cells at 1μg/ml within 24hrs.
It is agreed with previous reports that the partial changes of chemical structure of aflatoxins, for instance aflatoxin B
2 or tetrahydrodesoxo aflatoxin, encountered the different toxicities to the cell-system.
From above mentioned facts, it might safely be said that the present chicken embryo liver cell-system could be useful for the bioassay method of aflatoxin B
1.
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