Electron microscopic investigation of the source and direction of movement of lipid granules appearing in the hepatic perisinusoidal space following partial hepatectomy,

Abstract

AbstractThe early sequelae of partial hepatectomy were studied at the ultrastructural level in livers of CFW mice that had been maintained on a normal diet or fed a fat‐free diet for four days prior to surgery. Normal‐diet animals showed a marked increase in number of small osmiophilic lipid granules in hepatocytes and the space of Disse during the first post‐operative hour and at all later intervals studied. This observation generally confirmed similar findings on C3H mice by Trotter ('65), but failed to provide conclusive indications of the source or direction of movement (i.e., from extracellular space into hepatocyte by engulfment, or from hepatocyte to extracellular space by secretion) of the granules in the space of Disse. In livers of fat‐free‐diet animals, where small lipid granules synthesized in the hepatocyte are recognizable by their osmiophobia (being derived from lipogenesis they are relatively highly saturated), synthesis and secretion by hepatocytes accounted for substantially all lipid granules appearing in the space of Disse during the first three postoperative hours and continued to occur during the fourth hour. This finding demonstrates the importance of the liver cell as a source of lipid granules (presumably very low density lipoproteins) appearing in the space of Disse after hepatectomy. Osmiophilic granules presumed to be of enteric origin, which were present in the space of Disse in very small numbers during the first post‐operative hours, increased in number during the fourth hour. The exact fate of these granules and their importance, if any, in the “post‐hepatectomy picture” could not be determined from available data.