Galectin-3–induced activation of the NADPH-oxidase in in vitro primed neutrophils. The figure shows the time courses of the CL responses in primed neutrophils (10⁶ cells) induced by galectin-3 (20 μg/mL; a and d), galectin-3 in the presence of lactose (10 mmol/L; b and e), or collagenase digested galectin-3 (CRD; 20 μg/mL; c and f). The experiment was done with the primed cell population giving the largest response to galectin-3 (Fig 4), ie, ionomycin-treated cells for extracellular responses (a through c), and fMLP treated cells for intracellular responses (d through f). The responses were measured as in Fig 2 and are given as chemiluminescence (CL) units in megacounts per minute (Mcpm).