Alterations in Enzyme Activity of the Liver Lobule during Chronic Ethionine Injury¹

The metabolic response of the rat liver to chronic ethionine injury was studied at the level of the liver lobule by utilizing microdissection in conjunction with quantitative microchemical technics. The liver responds to ethionine injury by hyperplasia. The new cells formed in the periportal and central areas of the lobule contained less protein and had lower activities for most of the enzymes studied than did normal parenchymal cells in corresponding areas of the lobule from livers of pair-fed rats. However, on a dry weight basis, the protein content and the enzyme activities in both areas of the injured lobule exceeded control values. These excessive protein responses correlated temporally with the hyperplasia induced by ethionine and are of interest inasmuch as ethionine inhibits protein synthesis.