Figure 1.

Phagocytosis of fluorescent particles is reduced in peritoneal macrophages from old mice. Percentage of CD11b⁺/F4/80⁺ positive cells was assessed in peritoneal cells from young and old mice by flow cytometry. Representative dot plot and data combined from n = 8 mice (A). Total peritoneal cells were harvested from young and old mice, and macrophages were purified using an immunomagnetic negative selection kit. Macrophages were incubated with fluorescent particles (50 particles/cell) for 2 h and phagocytosis was analysed by flow cytometry (B). Mean fluorescence intensity (MFI) values were calculated (C), and the percentage of highly phagocytic macrophages in cultures from young and old mice was assessed (D). One representative experiment shown of three experiments, n = 4 per experiment. Mann–Whitney tests were performed for nonparametric data. Unpaired Student’s t-tests were performed for parametric data. *P < 0.05 *** P < 0.001.