Adaptive changes of the rat liver cells induced by repeated intraperitoneal injections of d-galactosamine. II. Light and electron microscopic investigations of hepatocellular nucleolar alterations.

The effects of repeated d-galactosamine (GalN) administration - i.e. subacute GalN intoxication - on rat liver cell nucleoli were examined. After an initial intraperitoneal injection of 375 mg GalN/kg body weight the rats were treated with 250 mg GalN/kg body weight daily at intervals between 24 h and 30 days. The rats were sacrificed six h after the last injection by decapitation. Specimens of liver were studied by light and electron microscopy. According to the nucleolar size three stages were to be distinguished. Stage I: decreased nucleolar size after one injection, stage II: increased and maximal nucleolar size after two to five injections, stage III: slightly increased relatively stable nucleolar size after six and more injections. Fine structural observations suggest a nucleolar hyperfunction in subacute GalN intoxication as well as a minor disturbance of the transcription and the transfer of the nucleolar RNA.