Fine structure and function of kupffer cells

Abstract

Kupffer cells are macrophages that are attached to the luminal surface or inserted in the endothelial lining of hepatic sinusoids. In this site, Kupffer cells play a key role in host defense by removing foreign, toxic and infective substances from the portal blood and by releasing beneficial mediators. Under some conditions, toxic and vasoactive substances also are released from Kupffer cells which are thought to play a role in a variety of liver diseases. Many of these activities may be modulated by the levels of gut derived endotoxin normally present in the portal blood. The ultrastructural aspects of Kupffer cell structure function in situ are best studied using perfused-fixed livers. In fixed livers, transmission and scanning electron microscopy reveal Kupffer cells during health to be irregular in shape with their exposed surfaces presenting numerous microvilli, filopodia, and lamellopodia. Long filopodia penetrate endothelial fenestrae to secure Kupffer cells to the sinusoid lining. Specific membrane invaginations known as worm-like bodies or vermiform processes are seen in the cytoplasm of Kupffer cells as are numerous endocytotic vesicles and lysosomes which vary in density, shape and size. Sometimes, annulate lamellae connected to the rough endoplasmic reticulum also are found. The principal endocytic mechanisms of Kupffer cells are phagocytosis of particulates and cells, and bristle-coated micropinocytosis for fluid-phase endocytosis of smaller substances. Many of these events are mediated by specific receptors. In some species, Kupffer cells can be distinguished from other sinusoidal lining cells and monocytes by specific cytoplasmic staining or monoclonal antibodies. Kupffer cells have been shown to be of monocytic origin as well as having the capacity for self-replication.

Morphological and histological study of the liver in migratory starling bird (Sturnus vulgaris)

“…VonKupffer cells are large cells with large basophilic nuclei and have several processes with an irregular or stellate outline that projects into the sinusoids. However, vonkupffer cells are located between the endothelial cells of the hepatic sinusoids and may play a role in removing foreign and toxic material from the portal blood and releasing beneficial mediators [24]. Additionally, there was a fine network of connective tissue fibers (collagen fibers) support the sinusoid (Figure 3 and Figure 6a).…”

Age-related changes in the hepatic microcirculation in mice

“…In a separate set of experimental animals (3 mice/group), routine methods were used to prepare liver specimens for transmission (TEM) and scanning (SEM) electron microscopy (McCuskey, 1986;McCuskey and McCuskey, 1990). Briefly, the livers are perfused through the portal vein with 0.1 M Na-cacodylate buffer to aid in washing out blood.…”

Three-Dimensional Surface Structure of Macrophages in Fetal and Adult Mouse Liver: An Immunohistochemical Light Microscopic Study

“…According to these observations, Kupffer cells possess numerous microvilli, filopodia and lamellopodia on their surface [McCuskey and McCuskey, 1990], and these ultrastructural surface features could also be recognized on images obtained by our three-dimensional reconstruction. Compared to confocal laser scanning microscopy, there were several disadvantages, such as lower resolution and thinner section thickness that could be evaluated.…”

“…The morphology of macrophages in various tissues has been extensively examined by both transmission electron microscopy and scanning electron microscopy, in particular in association with surface structures at the three-dimensional level [Dormans et al, 1990;McCuskey and McCuskey, 1990]. There are different functional subsets of macrophages, and macrophages in hematopoietic organs, including fetal livers in mice, have been known to play an important role in the proliferation and differentiation of erythroid hematopoietic cells as central macrophages of erythroblastic islets [Bessis, 1973;Sasaki and Iwatsuki, 1997].…”