Left ventricular remodeling after myocardial infarction in mice with targeted deletion of the NADPH oxidase subunit gp91PHOX

Background Oxidative stress is involved in progression of left ventricular hypertrophy and heart failure. Since NADPH oxidases are a major source of reactive oxygen species in the heart, we studied left ventricular remodeling after myocardial infarction in mice with targeted deletion of the NADPH oxidase subunit gp91(phox). Methods and results gp91(phox) knockout (KO) and wild-type (WT) animals underwent coronary artery ligation. Mortality was significant higher in the gp91(phox) KO mice. However, transthoracic echocardiography performed at days 1, 7, and 56 at mid-papillary levels revealed that progression of left ventricular remodeling was not influenced by the genotype. Moreover, systemic oxidative stress was not reduced in gp91(phox) KO mice as indicated by a significant increase in lipid peroxides potentially mediated by an increase of the NADPH subunit nox-1 in gp91(phox) KO mice. Conclusion Targeted deletion of the NADPH subunit gp91(phox) does not affect left ventricular remodeling following myocardial infarction and does not decrease the production of oxidative stress. However, the final role of the different NADPH subunits in the heart under pathophysiologic conditions remains to be determined.