Sammendrag
Endocytosis may originate both in coated pits and in uncoated regions of the plasma membrane. In hepatocytes it has been
shown that fluid phase endocytosis (here defined as 'pinocytosis') is unaffected by treatments that arrest coated pit-mediated
endocytosis, indicating that pinocytosis is primarily a clathrin-independent process. In this study we have tried to determine
possible connections between pinocytosis and clathrin-dependent endocytosis in rat hepatocytes by means of subcellular
fractionation, electron microscopy, and by assessing the influence of inhibitors of clathrin-dependent endocytosis on
pinocytosis. As marker for clathrin-dependent endocytosis was used asialoorosomucoid (AOM) labelled with [(125)I]tyramine
cellobiose ([(125)I]TC). [(125)I]TC-labelled bovine serum albumin ([(125)I]TC-BSA) was found to be a useful marker for
pinocytosis. Its uptake in the cells is not saturable, and any remnants of [(125)I]TC-BSA associated with the cell surface could
be removed by incubating the cells with 0.3% pronase at 0 degrees C for 60 min. The data obtained by electron microscopy
and by subcellular fractionation suggested that early after initiation of uptake (
Vis fullstendig beskrivelse