Characterization of the chemiluminescence response of polymorphonuclear leukocytes stimulated with urate crystals

We studied the luminol-amplified chemiluminescence (CL) response of human polymorphonuclear leukocytes (PMNLs) stimulated with synthetic monosodium urate monohydrate (MSUM) crystals. Stimulation of PMNLs prepared from healthy controls with MSUM resulted in a bimodal CL response with two peaks after 1 min and 4-6 min, respectively. MSUM caused neutrophils to produce reactive oxygen species (ROS), which are released from the cells as well as ROS with an intracellular localization. Proportionally more of the CL activity generated during the first peak was of extracellular origin. The MSUM-induced light-generating mechanism was azide-sensitive, required superoxide anion and was strongly suppressed by horseradish peroxidase.