Sequential Changes in Histochemical Localization and Releasability of Epoxide Hydrolase during Experimetal Hepatocarcinogenesis

The influence of chronic 2-acetylaminofluorene (2-AAF) feeding on the histochemical localization of epoxide hydrolase in liver tissue was studied. Epoxide hydrolase was detected in the cytosolic fraction and the incubated microsomal supernatant by electroimmunoassay during 2-AAF feeding. A general increase in hepatocyte staining was observed from week 1 to week 3 during the feeding of 2-AAF. Early foci, I.e. week 6, showed low or slight statining, while hepatocytes surrouding them were stained intensely. In contrast, in late hyperplastic nodules, epoxide hydrolase was localized only in nodular cells. There quite a difference between the foci and the late hyperplastic nodules. A histochemical study of epoxide hydrolase indicated a correlation between the intensity of staining and the amount of epoxide hydrolase in cytosol or releasability from incubated microsomes.

Hepatocarcinogenesis-2-Acetylaminofluorene-Epoxide hydrolase-Hyperplastic nodule-Rat