Role of GABA-ergic brain systems in the activating effect of diazepam

The antigen of bile canaliculi of the mouse hepatocyte: identification and ultrastructural localization

The AgB10 antigen of bile canaliculi of the mouse hepatocyte was identified using monoclonal antibodies. The Mr value of 116000 for AgB10 was measured by immunoblotting. The tissue localization of AgB10 was studied by light and electron microscopy using the immunoperoxidase technique. AgB10 was predominantly present on the microvillus membrane of bile canaliculi, the brush border of intestinal mucosa and apical surfaces of the epithelial cells in some other organs. A small amount of AgB10 was detected on the basolateral domain of the hepatocytes. AgB10 was specific for hepatocytes and was not found in the other cell types of the liver. In primary hepatocyte culture, AgB10 was localized on the surface of cells during the first 24 h, predominantly at the sites of cell-cell and cell-substratum contacts. After 48 h of culture AgB10 gradually disappeared from contacting cell surfaces and became concentrated only in the reconstituted bile canaliculi.

Ultrastructural localisation of alpha-fetoprotin (AFP) in regenerating mouse liver poisoned with CCL4. 1. Reexpression of AFP in differentiated hepatocytes

The AFP-synthesizing cells were identified by ultrastructural localization of the antigen in regenerating liver of adult mice after CCl4 poisoning. An indirect immunoperoxidase method with rabbit anti-mouse AFP and peroxidase conjugates of anti-rabbit IgG or their Fab' was used. Good preservation of AFP and tissue structure, and sufficient permeability for the conjugates were obtained after 20' prefixation of small liver specimens in 8% formaldehyde -0.05% glutaraldehyde followed by 16 h fixation in 8% formaldehyde. The intracellular localization of AFP observed in the light microscope in most cases corresponded to its synthesis and secretion. It was found in two cell types, both concentrated mainly in the perinecrotic zones and constituting only a small part of the whole cell population. Most of the AFP-producing cells were normal differentiated hepatocytes without any structural signs of damage. A few smaller cells with active AFP synthesis were present in some animals. By their ultrastructure they resembled the oval cells found during chemical hepatocarcinogenesis in rats.