Effects of inhaled nitric oxide on inflammation and apoptosis after cardiopulmonary bypass.
BACKGROUND
Cardiopulmonary bypass (CPB), a procedure often used during cardiac surgery, is associated with an inflammatory process that leads to lung injury. We hypothesized that inhaled nitric oxide (INO), which has anti-inflammatory properties, possesses the ability to modulate lung cell apoptosis and prevent CPB-induced inflammation.


METHODS
Twenty male pigs were randomly classified into four groups: sham, sham plus INO, CPB, and CPB plus INO. INO (20 ppm) was administered for 24 h after anesthesia. CPB was performed 90 min into INO treatment. BAL fluid and blood were collected at time 0 (before CPB), at 4 h after beginning CPB, and 24 h after beginning CPB (T24).


RESULTS
At T(24), BAL interleukin (IL)-8 levels and neutrophil percentages were elevated significantly in the CPB group. At T(24), INO reduced IL-8 concentrations and attenuated the increase of neutrophil percentage in the CPB-plus-INO group. Nitrite-plus-nitrate (NOx) concentrations were decreased significantly in groups without INO. Moreover, animals treated with INO showed higher rates of pulmonary apoptosis compared to their respective control groups except for the sham-plus-INO group, in which they were diminished.


CONCLUSIONS
These results demonstrate that NOx production is reduced after CPB, and that INO acts as an anti-inflammatory agent by decreasing neutrophil numbers and their major chemoattractant, IL-8. INO also increases cell apoptosis in the lungs during inflammatory conditions, which may explain, in part, how it resolves pulmonary inflammation.
El Kebir
Driss
D
Laboratory of Anesthesia, Department of Anesthesia and Research Center, Center Hospitalier de Universitie de Montreal, Hopital Notre-Dame, Deschamps Pavilion, Room FS-1136, 1560 Sherbrooke St East, Montreal, QC, Canada, H2L 4M1.
Hubert
Bernard
B
Taha
Rame
R
Troncy
Eric
E
Wang
Tianlong
T
Gauvin
Dominique
D
Gangal
Marius
M
Blaise
Gilbert
G
D000280:Administration, Inhalation; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D004195:Disease Models, Animal; D007249:Inflammation / Q000188:drug therapy* / Q000209:etiology; D007322:Instillation, Drug; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000188:drug therapy; D013552:Swine
D009569:Nitric Oxide