1990 Volume 21 Issue 1 Pages 43-52
The distribution and the dynamics of cell surface negative charge were studied in rat liver sinusoidal cells and hepatocytes by perfusion of cationized ferritin (CF) through the portal vein. When CF was perfused at 4℃, CF bound onto the membrane of the endothelial cells especially on their sinusoidal side. In hepatocytes, CF binding was restricted to the surface of the microvilli facing the Disse's space. Its population was larger along their tip portion. Thus, a cellular polarity is to be indicated in terms of the distribution of anionic sites on the surface membrane of both the endothelial cells and hepatocytes. When CF was perfused at 37℃, CF particle were found in clusters on the surface of endothelial cells especially on their sinusoidal side. In addition, the bound CF was taken up actively into endothelial cells and Kupffer cells. After 30 min of perfusion at 37℃, these incorporated CF was localized in coated and uncoated pits and vesicles. After 60 min at 37℃, uncoated and coated vesicles and multivesicular bodies appeared heavily labeled with CF. On the contrary, hepatocytes and Ito cells revealed only a small amount of incorporated CF even after 60 min of perfusion. When compared among the different regions in the hepatic lobules, the binding and the endocytosis of CF were more prominent in the perilobular sinusoid than in the centrolobular one. Thus, regional differences and the differences in cellular dynamics of hepatic tissues have been clarified in terms of the distribution and incorporation of anionic sites by use of the in situ perfusion of CF.
