Ultrastructural alterations of hepatocytes in the tumour-bearing, cachectic rat

Morphologic changes in the hepatocytes of tumour-bearing rats at the pre-cachectic and cachectic stages were studied by electron microscopy and were quantitatively analysed by a morphometric method. Ten male F-344 rats, subcutaneously inoculated with methylcholanthrene-induced sarcoma cells (TBR) were compared with ten pair-fed controls (CTR). There was no significant difference in the size of the cells or their nuclei, the number of mitochondria, or the number of lysosomes, between TBR and CTR at either the pre-cachectic or cachectic stage. Although the size of mitochondria of TBR was already significantly enlarged at the pre-cachectic stage, before the food intake of the TBR had decreased, the micro-structure within the mitochondria was unaltered. Marked differences were observed in the number, arrangement and distribution of the rough endoplasmic reticulum, all of which decreased significantly in TBR compared with CTR at both the pericentral and periportal zones. Changes at the periportal region were further pronounced at the cachectic stage. These results, distinct from the changes seen in simple starvation, may confirm a part of the biochemical evidence specific to tumour induced metabolic alterations.