RESUMO
BACKGROUND: MPO is an antimicrobial enzyme in the primary granule of neutrophil. MPO exhibits MPO-I, MPO-II, MPO-III using chromatography in human peripheral leukocytes. we investigated MPO isozymes from human leukocytes of peripheral blood. METHODS: Neutrophils were prepared from 5-8mL of peripheral blood in the group of normal persons (normal group) and the group of patients with neutrophilia (patient group). Their cells were adjusted to 2.4X10(7) cells and sonified. We got finally the crude MPO from which native PAGE was performed and treated with diaminobenzine and H2O2. RESULTS: Normal neutrophil MPO had MPO-1 and MPO-2. The expression rates of MPO-1 and that of MPO-2 were respectively 100%, 67.5% in the normal group and 56.6%, 30.2% in the patient group (P=0.000, P=0.000). The expression rate of combined MPO-1 and MPO-2 and that of MPO-1 without MPO-2 were respectively 67.6%, 32.4% in the normal group and 28.3%, 28.3% in the patient group (P=0.000, P=0.000). The expression of MPO-2 without MPO-1 and that of no MPO isozymes were respectively 0.0%, 0.0% in the normal group and 1.9%, 41.5% in the patient group (P=0.000, P=0.000). CONCLUSION: Normal neutrophil MPO expresses MPO-1 and MPO-2 usig native PAGE. The main MPO isozyme is MPO-1. Expressions of MPO isozymes are variable in the patient group.