Figure 2. Effect of Brefeldin A on the rate of apoA-I induced cholesterol efflux.
[3H]-cholesterol prelabeled adipocytes were incubated for 2 hours in DMEM with, or without, Brefeldin A (10 μg/ml) and with or without pka-apoA-1 (75 μg of protein/ml). The bars show the mean values of apoA-I induced cholesterol efflux (expressed as % of cellular radiolabeled cholesterol) and their corresponding S.E (n=11, control-basal PKA; n=8, BFA basal PKA; n=7 Control-activated PKA; n=6 BFA-activated PKA, where n represents the number of wells used). Average values of apoA-I induced cholesterol efflux were calculated as the difference between the mean values of cholesterol found in wells containing apoA-I and the corresponding values for wells without apoA-I. The SD of the differences was calculated as: SD= [SD2(apoA1) + SD2(blank)]1/2 . The statistical significance of the differences between the mean values of apoA-I induced cholesterol efflux was determined by one-way ANOVA. Significant differences (P<0.001) were obtained between control and BFA samples under either basal or elevated (in the presence of isoproterenol) cellular PKA activities.