FIGURE 1.

Neutrophils from poorly controlled diabetic subjects generate significantly increased superoxide regulated by iPLA₂. A, Neutrophils (25 × 10⁶/ml) isolated from healthy and diabetic subjects were resuspended in PBS and incubated at room temperature for a period of 15 min. Cells were then stimulated with 1 μM fMLP, and superoxide generation was evaluated using a superoxide dismutase-inhibitable cytochrome C assay. The intensity of the colorimetric reaction was measured in a microplate reader at 550 nm. Data is presented as the mean ± SEM in nanomoles of O₂⁻ for healthy (n = 27), well-controlled diabetes (n = 8), moderately controlled diabetes (n = 6), and poorly controlled diabetes (n = 13). B, Neutrophils (25 × 10⁶/ml) were incubated with the indicated concentrations of BEL for 15 min at 37°C and then washed once with PBS. Neutrophils were resuspended in PBS and incubated at room temperature for a period of 15 min. Cells were then stimulated with 1 μM fMLP, and superoxide generation was evaluated using a superoxide dismutase-inhibitable cytochrome C assay. The intensity of the colorimetric reaction was measured in a microplate reader at 550 nm. Data are represented as percent inhibition and are expressed as mean ± SEM for three different donors. C, Neutrophils (25 × 10⁶/ml) from healthy and diabetic subjects were incubated with BEL (20 μM) for 15 min at 37°C and washed once with PBS. Neutrophils were resuspended in PBS and incubated at room temperature for a period of 15 min and were then stimulated with 1 μM fMLP and superoxide generation evaluated. Data are shown as nanomoles of O₂⁻ expressed as mean ± SEM for six different donors.