[Changes in the nature of the hepatocyte proliferation in the liver and adenomatous nodes of mice in CC14-induced carcinogenesis].

A study was made of cell proliferation and DNA content in the liver of SWR mice after 1, 7, 41 and 52 administrations of CCl4 made at 3-4 daily intervals. After 41 and 52 administrations of CCl4 the liver of all the animals demonstrated multiple small nodules and single large nodes. Cell proliferation in liver and large nodes was analyzed by cytophotometry and radioautography with the use of double isotopic label. The proliferation pattern in the liver was shown to change during cancerogenesis. Unlike normal, a great number of cells were not polyploidized but were reproduced. As regards the cell content, the three adenomatous nodes examined differed from the surrounding parenchyma and from each other. On the whole, the degree of polyploidy in the nodes was much lower despite the fact that the population contained all the cell types, uni- and binuclear cells, up to those with the DNA content of 32c. All these cells and those from the surrounding liver were involved in proliferation. The cellular sources of nodular formations are discussed.