Localization of xanthine dehydrogenase in chicken liver.

Abstract

The immunohistochemical localization of xanthine dehydrogenase in chicken liver was examined by indirect immunostaining, using anti-chicken xanthine dehydrogenase antisera and peroxidase-labeled anti-rabbit gamma-globulin. The enzyme activity of xanthine dehydrogenase in isolated hepatocytes was assayed by the biochemical method. Immunostaining of hepatic tissue sections showed that the cytoplasm of hepatocytes, Kupffer cells and endothelial cells lining the hepatic sinusoid was intensely stained. In chickens fed with a standard food containing 20% protein, the specific activity of 100,000 xg supernatant fraction of homogenate of isolated hepatocytes was almost the same as that of the whole liver. When the chickens were fed on a protein-rich diet, the enzyme activity in supernatant of homogenized isolated hepatocytes was 2.3 times higher than that in normal liver. Both the immunohistochemical and biochemical data in this study are comparable to each other, and suggest that xanthine dehydrogenase mainly exists in hepatocytes.