Endocytosis of agarose in mouse peritoneal macrophages in vitro.
We have studied the endocytosis of tritium-labelled and of non-radioactive agarose in mouse macrophages in vitro. The endocytosis was greatest and most rapid in syngeneic mouse serum and in human serum, reaching a plateau after 12 h of incubation. Ten per cent serum was the minimum concentration giving optimal ingestion. The endocytosis appeared to be regulated by mechanisms involving complement factors C3 and B. Different pretreatments of sera, inactivating or depleting C3 and B, resulted in 70-80% reduction of endocytosis. Preincubation of agarose in untreated serum increased the endocytosis of agarose in heat-inactivated serum three-fold indicating that the essential factors were bound to agarose. Antibodies against C3 and B reduced endocytosis moderately but significantly.
D000818:Animals; D003165:Complement System Proteins; D004705:Endocytosis; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D008297:Male; D051379:Mice; D011134:Polysaccharides / Q000378:metabolism*; D012685:Sepharose / Q000378:metabolism* / Q000494:pharmacology
D011134:Polysaccharides; D003165:Complement System Proteins; D012685:Sepharose