Makropinocytosis

In principle, macropinocytosis follows the same pattern as phagocytosis. One difference is that here no large particles are taken up, but larger quantities of extracellular fluid with the nutrients and macromolecules dissolved in it (Sieczkarski SB et al. 2002).

The vesicles formed in this process are relatively large, 1 to 5 µm in diameter, and correspond in size to phagosomes. Phagocytosis and macropinocytosis can be distinguished mainly biochemically: different reaction cascades are involved in both mechanisms (Cardelli J 2001). The intracellular fate of macropinosomes varies depending on the cell type. In the vast majority of cell types, they are in close contact with the endosomal system and fuse with lysosomal compartments.

1. Bathori G et al (2004). Caveolae-an alternative endocytotic pathway for targeted drug delivery. Crit Rev Ther Drug Carrier Syst 21: 67-95.
2. Cardelli J et al. (2001) Phagocytosis and macropinocytosis in Dictyostelium: phosphoinositide-based processes, biochemically distinct. Traffic 2: 311-320.
3. Sieczkarski SB et al (2002). Dissecting virus entry via endocytosis. J Gen Virol 83: 1535-1545.
4. Huth E (2005) Cellular uptake and intracellular fate of particulate drug delivery systems. Inaugural dissertation for the award of the doctorate of the Faculty of Chemistry, Pharmacy and Geosciences of the Albert-Ludwigs-University Freiburg.
5. Mineo C et al (2001). Potocytosis. Robert Feulgen Lecture. Histochem Cell Biol 116: 109-118.