Leukotoxin (9, 10-epoxy-12-octadecenoate) impairs energy and redox state of isolated perfused rat lung.
We investigated the perturbation of energy balance and redox state in leukotoxin (9, 10-epoxy-12octadecenoate) (Lx)- and endothelin-1 (ET-1)-induced lung injury, using isolated perfused rat lungs. To examine any relationship between these parameters, intracellular levels of adenine nucleotides, pyridine coenzymes and glutathione were determined by reversed-phase high-performance liquid chromatography (HPLC) in the freeze-dried tissues of isolated rat lungs. The tissue samples were perfused with a physiological salt solution containing either Lx only, Lx plus NG-monomethyl-L-arginine (L-NMMA), Lx plus NG-monomethyl-D-arginine (D-NMMA), Lx plus superoxide dismutase (SOD) or ET-1 only. In isolated perfused lung tissue, 10 mol of Lx caused permeability-increased lung injury, and 10 nM of ET-1, which caused a comparable increase in wet lung weight, evoked pulmonary capillary hypertensive lung injury. Lx-injured lungs showed decreases in the contents of ATP, NADPH, NADH, reduced glutathione (GSH), (2ATP + ADP)/2(ATP + ADP + AMP) ratio (energy charge) and NADH/NAD+ ratio, and increased the contents of ADP and AMP compared with the vehicle control and ET-1-injured lungs. Such effects of Lx were significantly attenuated by pretreatment with 0.4 mM L-NMMA or 500 units/ml of SOD, but not with 0.4 mM D-NMMA. On the other hand, the ET-1-injured lung evidenced decreased tissue GSH. These findings indicate that Lx shifted the lung redox state toward oxidation and that Lx-induced lung injury was involved in the imbalance of the energy and redox state via production of nitric oxide and/or superoxide anion.
Akai
M
M
Third Department of Internal Medicine, Faculty of Medicine, Fukui Medical University, Japan. makaifmsra@fukui-med.ac.jp
Ishizaki
T
T
Matsukawa
S
S
Shigemori
K
K
Miyamori
I
I
D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D019332:Endothelin-1 / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D008041:Linoleic Acids / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D014118:Toxins, Biological
D000227:Adenine Nucleotides; D019332:Endothelin-1; D008041:Linoleic Acids; D014118:Toxins, Biological; D009243:NAD; D009249:NADP; C051208:9,10-epoxy-12-octadecenoic acid; D005978:Glutathione