Figure 1.

(A) Structure of ¹⁸F-MAPP. (B) ¹⁸F-MAPP can cross the cell membrane. After neutrophils were incubated with ¹⁸F-MAPP for 1 h and then washed to remove ¹⁸F-MAPP in the medium, radioactivity was still found in the neutrophils. Interestingly, the uptake was significantly higher at 37 °C than that at 4 °C, suggesting intracellular uptake may have both passive diffusion and energy-dependent components (* p < 0.05, n = 4, two-tailed t-test. Radioactivity was normalized to protein amounts obtained from BCA protein assay after gamma counting).