Fine structure of rat hepatocytes during the late phase of chronic 2-acetylaminofluorene intoxication

Abstract

Male Leeds strain rats were fed a diet containing 0.05% of 2-acetylaminofluorene (2-AAF) for 8–10 months. Their liver tissue was then examined by electron microscopy. The hepatocytes were variable in their ultrastructural morphology and showed the presence of a number of cytoplasmic changes and, infrequently, nucleolar microsegregation. Some changes, including glycogen depletion, atrophy of the Golgi apparatus and bizarre forms of mitochondria and endoplasmic reticulum, appeared to be related to chronic 2-AAF toxicity. It seemed that others, which were irreversible, might be more specifically associated with the carcinogenic action of this agent. These included changes in cell surface morphology, depletion and redisposition of the granular endoplasmic reticulum, hypertrophy of the agranular endoplasmic reticulum and reduced mitochondrial size. The possible significance of the observed changes is discussed.