Ultracytochemical Observations on Minute Osmiophilic Structure in Hepatocytes of Phalloidin-injected Rats

Abstract

In the hepatocytes of adult female rats injected i. p. daily with 0.5 mg/kg of phalloidin for a week, some minute, flocculent and osmiophilic structures were observed sporadically in the cytoplasms adjoining to accumulating foci of markedly hyperplastic microfilaments surrounding an abnormal bile canaliculus. The particular structures were examined ultracytochemically with both so-called “enzymic digestive methods for lipids” proposed by the authors and a double fixation method using tannic acid, and they were indicated to contain much more phospholipids and cholesterol esters. These minute osmiophilic structures, therefore, might be resulted from the deposition of biliary lipids, which was induced by microfilament dysfunction within the livers. A moderate accumulation of hyperplastic microfilaments around the bile canaliculi 3days after the daily injection of phalloidin did not modify an initial stage of ethionine-induced triglyceride fatty liver. Lipid traffic in the hepatocytes was discussed from a standpoint of cytoskeletal pathology.