Oxygen radical production by horse and pig neutrophils induced by a range of crystals.

The exposure of animal neutrophils to crystals implicated in joint inflammation induces superoxide and peroxide generation in a concentration and temperature dependent fashion. Active crystals were urate, hydroxyapatite, pyrophosphate and brushite; diamond and cholesterol were inactive. Cytochalasin B increased superoxide yield after addition of brushite, and inhibitors of the PMA induced respiratory burst blocked the crystal induced response. Addition of urate to anaerobic neutrophils causes the reduction of a b-type cytochrome, a likely component of the neutrophil superoxide generating system.