Macrophages. Inhibition of endocytosis by anchorage to substrate.

The rates of non-specific endocytosis and of binding of liposomes by mouse peritoneal macrophages diminish markedly after anchorage of the cells to a polystyrene substrate. After detachment from the substrate, the cells regain both endocytic and sorbtive abilities. This observation may explain the variability of data on endocytosis and should be taken into consideration in standardization of conditions of macrophage studies.