Vacuolar Degeneration of Rat Liver Cells by Electron Microscopy

Abstract

BIOCHEMICAL studies on the vacuolar degeneration of rat liver cells have been carried out in this Institute during the past three years. Total and residual nitrogen fractions, cateptic and transaminase activities, acid-soluble SH-groups, intra- and extra-cellular water fractions have been studied on normal and vacuolated rat liver. Vacuolation was obtained by keeping the animals in an atmosphere of 3 per cent oxygen + 97 per cent nitrogen for 2 hr. No changes were observed in the nitrogen and water fractions, in cateptic and transaminase activities, in SH-groups, or deoxyribonucleic and ribonucleic acid contents; only some of the soluble phosphorus fractions were diminished. These results therefore seem to lead to the conclusion that the cytoplasmic lesions are not so serious as one would expect them to be from the morphological appearance of the vacuolated cells. In fact, the cytoplasm of these cells appears deeply damaged in stained sections and contains several vacuoles of different size, which may sometimes reduce the cytoplasm to thin strands between the vacuoles. However, observations carried out with a phase-contrast microscope on isolated living liver cells from animals kept in hypoxia indicate that vacuoles are not visible in non-fixed, unstained cells. This seems to suggest that the appearance of these vacuoles is linked in some way with fixation of the damaged cells: it could be an artefact due to the action of the fixatives commonly used in histology on the cytoplasmic structures.