Other

systemic errors can influence the results, including estimates of sizes of nuclei with irregular shapes, such as those characteristic of Kupffer cells. The method of Abercrombie [33] is not as powerful as more modern stereological techniques, but was chosen because we did not have the sequential sections necessary for strict stereological approaches. Numbers of Kupffer cells, relative to numbers of putative hepatocytes, appear low early in development, compared to the adult state [22]. This may seem surprising in light of the selleck screening library suggested phagocytic role for Kupffer cells during the early phase of hemotopoesis in the liver. Numbers of Kupffer cells of course relies upon the validity of F4/80 immunoreactivity. Whatever the function

(currently not selleck chemicals llc well understood) of the F4/80 antigen, it may have different distributions and antigenicity in the developing as compared with the mature liver. Previous studies [34, 35] have demonstrated that Kupffer cells can be identified even in the fetal liver, by ARS-1620 in vitro their phagocytic ability and expression of their F4/80 immunoeactivity. Further, hepatocytes can be identified by a variety of transcription factors and proteins, including albumin [[35–37]]. The spatial distributions of F4/80 positive cells and of the 0.2 μm diameter microsphere containing cells seen in developing mouse liver are similar to distributions of those same markers seen in the adult. Liver

tissue collected from animals from 15 to 24 days of age appeared indistinguishable from that of adults, as regards the distribution and apparent intensity of F4/80 or microsphere labelling. Microsphere labelling was Acesulfame Potassium evident even at the youngest ages studied (P0 to P3), as was immunoreactivity to the F4/80 antibody and, as in the adult, these two markers were largely co-localized in the same cells. At the fine structural level [21], F4/80 immunoreactivity appears associated with the plasmalemmae of Kupffer cells. While the F4/80 antibody is commonly used as a marker for macrophages throughout the body, the cellular function of the antigen itself is not known. Morphological differences are apparent between F4/80 positive cells taken from early postnatal liver tissue and those taken from mature animals. Mature Kupffer cells are morphologically complex, with extensive dendritic-like processes. In the early postnatal period, the dendritic processes appear less extensive, although longer and broader processes are common by P11. Whether these apparent morphological differences are due to real structural differences of the cells at different ages or due to differences in distribution of the F4/80 identified antigen is not clear at this time.