ZINC HYDROXIDE INDUCED RESPIRATORY BURST IN RAT NEUTROPHILS

The effects of zinc hydroxide on the respiratory burst and phagocytosi s by rat neutrophils were examined. Zinc hydroxide induced an increase in oxygen consumption and O-2(-), production. Electronmicroscopy show ed that neutrophils engulfed zinc hydroxide particles by phagocytosis. Pertussis toxin (0.25, 0.5, 1.0 mu g/ml) and EGTA (1, 2, 5 mM) inhibi ted zinc hydroxide-induced O-2(-) production in a dose-dependent manne r. The inhibitors of protein kinase C, 1-(5-isoquinolinesulfonyl)-2-me thylpiperazine and N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide inhibited zinc hydroxide-induced O-2(-) production with IC50 values ra nging between 10 mu M and 25 mu M. The inhibitory study using an inhib itor of myosin light chain kinase, 1-(5-iodonaphthalene-1-sulfonyl)-1H -hexahydro showed IC50 values ranging from 5 mu M to 10 mu M. These fi ndings indicate that zinc hydroxide induces respiratory burst and phag ocytosis by rat neutrophils.