A quantitative study of pinocytosis and intracellular proteolysis in rat peritoneal macrophages.
A method for the culture of rat peritoneal macrophages in vitro is described, in which pinocytic uptake of colloidal [198 Au]gold, 125I--labelled poly(vinylpyrrolidone) and [14C]sucrose proceeds at contant and fairly reproducible rates for several hours. The rat of uptake of colloidal [198 Au]gold, which wxhibited some inter-batch variation, was approx. 100 times that of the other two substrates. Colloidal gold did not affect the rate of uptake of 125I-labelled poly(vinylpyrrolidone) and therefore its own high rate of uptake could not be attributed to a stimulation of the formation of pinocytic vesicles. It conclude that uptake of collodial gold is highly dependent on adsorption on binding sites on the plasma membrane. Uptake of formaldehyde-treated 125I-labelled bovine serum albumin was followed by the release of [125I]iodo-L-tyrosine into the culture medium and took place at a rate intermediate between those of collodial [198Au]gold and the other two non-digestible substrates, 125I-labelled poly(vinylpyrrolidone) and [14C]sucrose.
D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D002478:Cells, Cultured; D005557:Formaldehyde; D006048:Gold Colloid, Radioactive; D007457:Iodine Radioisotopes; D008264:Macrophages / Q000378:metabolism*; D010873:Pinocytosis; D011205:Povidone / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
D006048:Gold Colloid, Radioactive; D007457:Iodine Radioisotopes; D011506:Proteins; D005557:Formaldehyde; D012710:Serum Albumin, Bovine; D013395:Sucrose; D011205:Povidone