EVIDENCE THAT HEPATOCYTES CAN PHAGOCYTIZE EXOGENOUS SUBSTANCES

Although the phagocytic action of Kupffer cells is well known, such a phenomenon has not been well documented for hepatocytes. Following the injection of a suspension of egg lecithin-coated silicon particles (0.5-1.5-mu-m in diameter) into the portal vein of rats, Kupffer cells showed minimal phagocytotic action, which was in contrast to the hepatocytes which displayed numerous phagocytized silicon particles. By comparison, when noncoated silicon particles of the same diameter as those that were coated were injected into the portal vein, the opposite observation was made. There was no uniformity in the ability of the hepatocytes to phagocytize either coated or noncoated particles from one lobule to another. Some showed active phagocytosis, while in others no evidence of such a process was observed. These data provide strong evidence for the selective phagocytic action of liver hepatocytes.