Figure 3: Effects of corticosterone on the phagocytosis of rat peritoneal macrophages. Rat peritoneal macrophages were cultured in 96-well plates and then incubated with bacteria expressing dsRed-tagged ovalbumin for 30 min at 37°C under 5% CO2. The macrophages were fixed using 4% paraformaldehyde. The phagocytic activity was determined by evaluating the ability to intake bacteria using confocal microscopy. (a) Rat peritoneal macrophages were treated with vehicle diluent (ethanol) as a control group. Macrophages were treated with 30 nM, 150 nM, and 3 μM corticosterone, respectively. Scale bar, 37.5 μm. The phagocytic activity was estimated by the phagocytic rate (b) and index (c). The results were representative of five independent experiments performed on triplicate samples. * versus the control group.