Effects of prolonged oral treatment with N-fluoren-4-ylacetohydroxamic acid on rat liver fine structure.

Inbred male Leeds strain rats were given a diet containing 0.05% N-fluoren-4-ylacetohydroxamic acid for up to 7 months. A modified method for the synthesis of this compound is described. Rats were killed at intervals during and after treatment and their liver tissues examined by light and electron microscopy. The treated rats developed a very low incidence of (non-hepatic) tumours and hepatic clear cell foci appeared during the late stages of the experiment. The only significant fine structural changes observed were glycogenosis and alterations in the morphology of the rough endoplasmic reticulum, both of which developed only after prolonged treatment and affected a minority of hepatocytes. These changes are discussed in relation to the fine structural changes elicited by the strongly carcinogenic N-fluoren-2-ylacetamide and the non-carcinogen, N-fluoren-4-ylacetamide.