Ultrastructure of the Liver in Response to Cyclophosphamide and Triterpenoids

Ultrastructural reorganization of liver cells after isolated injections of cyclophosphamide, betulonic acid or its β-alanylamide, and combined treatment with the cytostatic and each of the triterpenoids is studied. Cyclophosphamide causes significant ultrastructural changes in all intracellular compartments of hepatocytes. Both triterpenoids cause moderate cytotoxic and stimulatory effects on the liver cell populations (hepatocytes, sinusoidal endotheliocytes, and Kupffer cells), when used alone. The cytotoxic effect of betulonic acid manifests in modification of the fine structure of hepatocyte mitochondria, sequestration of glycogen, intensification of autophagic processes, emergence of necrobiotic changes in hepatocytes and endotheliocytes; betulonic acid amide actively modifies the mitochondrial fine structure (hypertrophic organelles, matrix rarefaction, uneven dilatation of cristae). The effects of combinations of cyclophosphamide with betulonic acid or its amide on liver are polytarget: the cytotoxic activity of the cytostatic is potentiated towards some cells, while in other cells the regeneratory reactions are stimulated. The common cytological cytoprotective effects of betulonic acid and its amide used alone and in combination with cytostatics include stimulation of the endocytotic (pinocytotic) activities of the cells and stimulation of intracellular regeneration processes in them.