Kupffer cells phagocytosis

Husztik, E., Lazar, G. Rarduez, A. (1980) Eleetton microscopic study of Kupffer-cell phagocytosis blockade induced by gadolinium chloride. Br. J. exp. Pathol., 61, 624-630... 

The use of the reticulo-endothelial system (RES) was the first approach to liver contrast agents. As an adjunct, spleen imaging would also be possible with a contrast agent that is taken up by the RES. The Kupffer cells of the liver, which represent 10% of all hepatic cells, constitute the major portion (80-90%) of all fixed macrophages and they are extremely effective in the phagocytosis of all types of particles. The downside of the use of this mechanism, however, is the concomitant release of toxic mediators that might and - as a matter of fact - often has made this approach non-feasible. Adverse events provoked by the mediators are changes in blood pressure (most often hypotension) and fever. 

A more orderly type of cell death is apoptosis, in which the cells become encapsulated and are systematically removed from the organ. This essential housekeeping function is accomplished in the liver by special cells called Kupffer cells. These cells perform phagocytosis, in which a solid particle, such as a cell remnant or other foreign matter in the liver, becomes encapsulated in a plasma membrane and incorporated into the Kupffer cell, which is then eliminated. 

Palmer DI, Rifkind D, Brown DW (1971) l-labeled colloidal serum albumin in the study of reticuloendothelial system function. III. Phagocytosis and catabolism compared in normal, leukemia, and immunosuppressed human subjects. J Infect Dis 123 465-469 Ponto JA, Swanson DP, Freitas JE (1987) Clinical manifestations of radio-pharmaceutical formulation problems. In Hladik WB III, Saha GB, Study KT (eds) Essentials of nuclear medicine science. Williams Wilkins, Baltimore, pp 268-289 Reske SN, Vyska K, Feinendegen LE (1981) In vivo assessment of phagocytic properties of Kupffer cells. J Nucl Med 22 405... 

Cathepsin D is a lysosomal protease present in normal cells at a very low concentration. It is first produced in a precursor form, pro-cathepsin D (52 kDa), and the processed in the cell to an intermediate form of 48 kDa, then finally to the mature forms of 34 kDa and 14 kDa. Phagocytosis of intravenously injected IgG-coated sheep red blood cells by rat liver Kupffer cells did not change the activity of cathepsin D (Brouwer et al. 1981). 

Kupffer cells are major targets for lipopolysac-charides. Hepatic macrophages engulf lipopolysac-charide by phagocytosis (Mathison and Ul-EviTCH 1979). Lipopolysaccharide increased Oj " production in Kupffer cells (Bautista et al. 1990). Additionally, Upopolysaccharide induces migration of activated polymorphonuclear neutrophils into the Uver (Levy et al. 1967). Since these cells are the other source of free radicals, the intensity of polymorphonuclear neutrophil infiltration determines the degree of hepatic endotoxemia (Hewett et al. 1992). 

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