Endocytosis and Digestion in Entamoeba Histolytica.

Abstract

Internalization of particulates and liquids (endocytosis) and the assymilation of ingested foodstuffs have been well documented for several free living amebae (Pelomyxa and Acanthamoeba). Less is known about these processes in the human parasitic ameba, Entamoeba histolytica.Axenically cultivated trophozoites of E. histolytica, strain HM-1:IMSS, were studied by transmission electron microscopy of thin sections and freeze-etch replicas prepared from cells incubated (5 min to 3 hr) with latex beads, erythrocytes or bacteria.Tubular channels formed by plasmalemma invagination appeared to be associated with pinocytosis (Fig. 1). These were similar to the pinocytotic channels described by Chapman-Andreson and Nilsson for Pelomyxa.