[Morphologic findings in liver tissue in mice after long-term administration of the herbicide fomesafan].

Administration of herbicide fomesafen and of fomesafen combined with one dose of iron to 44 mice during 3 to 14 months caused hyperplastic and preneoplastic changes in the liver tissue which had been described in experimental carcinogenesis* small groups of altered hepatocytes storing glycogen or lipids and foci of small basophilic liver cells occurred as early as after 3 months. Altered hepatocytes were found more frequently in mice getting fomesafen and iron. Later nodular hyperplasia of liver cells developed with nodes 3-20 mm in diameter which mostly consisted of altered hepatocytes with plenty of glycogen. After 12 and 14 month-lasting administration of fomesafen and fomesafen with iron, the hepatocellular carcinoma was proved in 5 mice. In 4 mice, the preneoplastic changes in liver tissue were accompanied by micronodular hyperplasia of liver cells which did not participate on the development of big nodes and hepatocellular carcinoma.