LYSOSOMAL CHANGES IN RAT HEPATIC PARENCHYMAL CELLS AFTER GLUCAGON ADMINISTRATIONI

Endocytosis of lysosomal enzymes by non-parenchymal rat liver cells. Comparative study of lysosomal-enzyme uptake by hepatocytes and non-parenchymal liver cells.

Cultured non-parenchymal rat liver cells internalize human urine alpha-N-acetylglucosaminidase, human skin beta-N-acetylglucosaminidase and pig kidney alpha-mannosidase. Different heat-stabilities of endocytosed and endogenous alpha-mannosidase activity provided indirect evidence that the increase in intracellular activity resulted from uptake. The high efficiency and the saturation kinetics of...

Regulation of coenzyme A biosynthesis by glucagon and glucocorticoid in adult rat liver parenchymal cells.

We studied the effects of glucagon, dibutyryl cyclic AMP and dexamethasone on the rate of [(14)C]pantothenate conversion to CoA in adult rat liver parenchymal cells in primary culture. The presence of 30nm-glucagon increased the rate by about 1.5-fold relative to control cultures (range 1.4-2.3) and 2.4-fold relative to cultures containing 1-3m-i.u. of insulin/ml. The half-maximal effect was ob...

Nucleoside uptake in rat liver parenchymal cells.

Rat liver parenchymal cells express Na(+)-dependent and Na(+)- independent nucleoside transport activity. The Na(+)-dependent component shows kinetic properties and substrate specificity similar to those reported for plasma membrane vesicles [Ruiz-Montasell, Casado, Felipe and Pastor-Anglada (1992) J. Membr. Biol. 128, 227-233]. This transport activity shows apparent K(m) values for uridine in ...

Quantitation of acid phosphatase and aryl sulphatase in rat hepatic parenchymal and kupffer cells.

The two acid hydrolases ‘acid phosphatase’ (orthophosphoric monoester phosphohydrolase, EC 3.1.3.2) and ‘aryl sulphatase’ (aryl-sulphate sulphohydrolase, EC 3.1.6.1) are both enzymes which are known to be present in the lysosomes of almost all cell types [cf. l] . Histochemical studies have revealed apparent activity of acid phosphatase in both hepatic parenchymal and Kupffer cells [2,3] , and ...

Transient Hepatic Parenchymal Enhancements