Figure 9.

Expression of the type II InsP3R in normal and cholestatic human liver. Confocal immunofluorescence images were obtained from paraffin-embedded liver biopsy specimens. Each tissue section was double-labeled with antibodies directed against the type I InsP3R (red) and type III InsP3R (green). (A) Normal liver. Expression of the type II InsP3R is low in normal cholangiocytes compared with hepatocytes, and the type III InsP3R is concentrated in the apical region of cholangiocytes. Note that the type II InsP3R is concentrated in the canalicular region of hepatocytes, as has been reported.⁶⁷. (B) Bile duct obstruction. Neither the type II nor the type III InsP3R is detectable in cholangiocytes. Findings are representative of 3 separate biopsy examinations. (C) Primary biliary cirrhosis. Neither InsP3R isoform is detectable in cholangiocytes, even though hepatocytes continue to express the type II InsP3R. Findings are representative of 3 separate biopsy examinations. Scale bars = 30 μm.