ALTERATION OF THE STRUCTURE AND FUNCTION OF GUINEA-PIG PERITONEAL-MACROPHAGES BY A SOYBEAN OIL EMULSION

  • 1 January 1979
    • journal article
    • research article
    • Vol. 96  (3) , 753-+
Abstract
PARENTERAL HYPERALIMENTATION has been widely used in the treatment of adults and children with gastrointestinal abnormalities and malnutrition. Intralipid (IL), a 10% emulsion of soybean oil stabilized with 1.2% egg yolk phospholipid, is now being used as a major constituent of hyperalimentation fluids. Studies in humans who have received IL demonstrated the presence of a fat pigment and fat droplets in reticuloendothelial phagocytic cells. Clinical data and in vitro studies suggest that these cells do not function normally. The effect of IL on the morphology and function of guinea pig peritoneal macrophages was studied in vitro. Starch-induced macrophages were exposed to IL for up to 48 h. Ingestion of increasing amounts of IL over the 48 h period was confirmed by transmission electron microscopy and by oil red O stain. The uptake of the IL was associated with marked morphologic changes characterized by a decreased ability of the cells to spread and by a decrease in the number and degree of complexity of the membrane ruffles. The ingestion of IL also resulted in decreased capacity of the cells to associate with latex beads (5.7 .mu. in diameter) or Candida albicans and decreased capacity to adhere to and ingest sheep erythrocytes coated with [immunoglobulin G]. After ingestion of latex beads 0.46 .mu. in diameter, which are similar is size to IL particles, macrophages had normal morphology and function. Neither the morphologic nor functional abnormalities were due to a nonspecific effect of ingestion of small particles. Alterations of human reticuloendothelial macrophage function similar to the effects observed could compromise host defense against infection.