[Acidification kinetics in macrophage phagosomes based on flow cytometric data]

Using flow cytofluorimetry, acidification in macrophages was studied during phagocytosis of yeast cells Candida albicans conjugated with FITC. Two phases of acidification were found: one corresponding presumably to yeast cell absorption on the macrophage surface, and the other one being due to cell incorporation into phagolysosomes. The phases are characterized by pH values of 6.3 +/- 0.5 and 4.5 +/- 0.5, respectively. Addition of 10 mM NH4Cl cancelled the observed acidification, whereas the presence of cytochalasin B (2 . 10(-5) M) prevented the very process of acidification.