Characterization of Kupffer cells in livers of developing mice

Sections of liver tissue from early postnatal mice were prepared using immunocytochemical techniques. The Kupffer cells were identified by their immunoreactivity to the F4/80 antibody, whereas endothelial cells were labelled with the CD-34 antibody. In addition, Kupffer cells and endothelial cells were labelled by systemically injected fluorescently labelled latex microspheres. Tissue slices were examined by fluorescence microscopy.Intravenous or intraperitonal injections of microspheres yielded similar patterns of liver cell labelling. The F4/80 positive Kupffer cells were labelled with both large (0.2 μm) and small (0.02 μm) diameter microspheres, while endothelial cells were labelled only with the smaller diameter microspheres. Microsphere labelling of Kupffer cells appeared stable for at least 6 weeks. Cells immunoreactive for F4/80 were identified as early as postnatal day 0, and these cells also displayed uptake of microspheres. Numbers of F4/80 Kupffer cells, relative to numbers of albumin positive hepatocytes, did not show a significant trend over the first 2 postnatal weeks.Kupffer cells of the developing mouse liver appear quite similar to those of other mammalian species, confirming that the mouse presents a useful animal model for studies of liver macrophage developmental structure and function.The important roles performed by the liver in the storage and release of nutrients and in the neutralization and elimination of a variety of toxic substances have prompted investigations of its cellular constituents and organization. Some of these studies have been carried out in human liver, but the importance of having an experimental model system has prompted several investigations of liver organization in laboratory mammals, primarily rats [1-7]. In species studied thus far, investigations have demonstrated that the liver is comprised of parenchymal cells, the hepatocytes [8-10], and a variety of non-parenchymal resident cells including a population of macroph