title: Effect of molecular size of 125I-labelled poly(vinylpyrrolidone) on its pinocytosis by rat visceral yolk sacs and rat peritoneal macrophages.
abstract: Rates of pinocytosis of different molecular-weight distributions of 125I-labelled poly(vinylpyrrolidone) by rat visceral yolk sacs and rat peritoneal macrophages were measured in vitro. Four preparations of mean molecular weights 50 000, 84 000, 700 000 and 7 000 000, were used. Macrophages captured the highest-molecular-weight preparation more rapidly than the other preparations. In contrast, rate of capture by the yolk sac decreased with increasing molecular weight. Incubations with a very-high-molecular-weight fraction derived from the 7 000 000-average-mol. wt. preparation clearly demonstrated that very large polymer molecules are not accumulated by the yolk sac, but are preferentially captured by macrophages. Analysis of the 125I-labelled poly(vinylpyrrolidone) internalized by the two cell types confirmed that low-molecular-weight material is preferred by the yolk sac, whereas the macrophage is less discriminating.
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D066298:In Vitro Techniques; D007454:Iodides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D008970:Molecular Weight; D010873:Pinocytosis / Q000187:drug effects*; D011205:Povidone / Q000031:analogs & derivatives*; D011206:Povidone-Iodine / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors; D015017:Yolk Sac / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D007454:Iodides; D011206:Povidone-Iodine; D011205:Povidone