The Effects of Carbenoxolone on the Biosynthesis of Gastric Glycoproteins in the Rat and Ferret

8-naphthylamidase and y-glutamyl transpeptidase were more complex. The leucyl-finaphthylamidase showed significant amounts of activity remaining in the sample layer with a broad distribution throughout the gradient. There were peaks of activity corresponding to 5'-nucleotidase (plasma membrane), N-acetyl-fi-glucosaminidase (lysosomal) and neutral a-glucosidase (microsomal) suggesting a multi-organelle localization. y-Glutamyl transpeptidase showed little soluble activity and a complex distribution pattern which did not conform to any of the known marker enzymes. This would indicate a unique subcellular distribution and histochemical studies have suggested a localization of this enzyme to the biliary canaliculi (Hagerstrand, 1973). These analytical techniques have been applied to liver tissue obtained in a variety of hepatic diseases. Striking increases in activity were found for certain of these enzymes. Preliminary results indicate that there is a significant positive correlation between serum and tissue activities for enzymes predominantly localized to the plasma membrane (5'-nucleotidase, alkaline phosphatase), but there is no such relation for lysosomal and for other membrane-bound enzymes. This study applies microanalytical subcellular fractionation techniques, for the first time, to human liver biopsies. The principal organelles : plasma membrane, mitochondria, lysosomes, peroxisomes and microsomal fractions were resolved and some of their properties described. Preliminary studies were made of changes in these organelles in diseased liver.