Superoxide production by rat neutrophils in the oleic acid model of lung injury

The purpose of this study was to investigate the superoxide anion (O 2 −)-generating capacity of neutrophils isolated from rats ar various of oleic acid(OA)-induced lung injury. Neurophils were collected from blood, bronchoalveolar lavage (BAL), and cavity (glycogen induced) after OA administration. Control neutrophils were collected from the blood of normal animals as representive of nonprimed cells that produce low levels of O 2 −. A second control was the glycogen-elicited peritoneal neutrophil of normal animals which represented cells that produce enhanced levels of O 2 −. The ability of the neutrophils to produce O 2 − was evaluated by using both phorbol myristate acetate and opsonized zymosan as stimulants. Neutrophils isolated from blood and BAL from OA-injured lungs produced low levels of O 2 − and resembled closely the circulating, nonprimed nutrophil. Myeloperoxidase levels were measured in plasma and BAL and were found to be elevated in BAL of OA-injured animals. The ability of neutrophils to produce high levels of O 2 − and the elevation of myeloperoxidase suggest that neutrophils present in the lung may have degranulated in response to prior activation and are therefore incapable of further superoxide production.