INCREASED NITRIC-OXIDE BIOSYNTHESIS IN LEUKOTOXIN,9,10-EPOXY-12-OCTADECENOATE INJURED LUNG

We measured effluent nitric oxide levels using a chemiluminescence met hod from leukotoxin (Lx, a linoleate epoxide) injured isolated rat lun gs perfused with physiological salt solution. Nitric oxide production from Lx-injured lung promptly increased and lasted for 20 min. Pretrea tment with N-G-monomethyl-L-arginine (LNMMA) significantly suppressed Lx-induced production of nitric oxide. Effluent from control lungs sho wed trace levels of nitric oxide. The wet to dry lung weight (WLW/DLW) after termination of the experiments was significantly elevated in Lx -treated lungs compared with that of LNMMA pretreated lungs or control lungs. There was a correlation between nitric oxide levels (at 10 min ) and lung edema (WLW/DLW). Thus, nitric oxide plays a role in the pat hogenesis of Lx-induced lung injury. (C) 1995 Academic Press, Inc.