Spontaneous lung chemiluminescence upon paraquat administration.

In vivo rat lung chemiluminescence was measured at different times after a single injection of either 30 or 60 mg paraquat/kg b.w. The lungs were isolated to determine myeloperoxidase (index of polymorphonuclear leukocytes), lung wet weight (lung edema) and malondialdehyde (lipid peroxidation). The highest chemiluminescence was reached 30 hours after injection of 30 mg/kg or 6 hours after a 60 mg/kg dose. The peak chemiluminescence was coincident with the maximum concentration of myeloperoxidase and lung wet weight suggesting that most chemiluminescence was the consequence of polymorphonuclear activation after migration to the injured areas.