Figure 4

Superoxide production and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity as well as expression of NADPH oxidase subunit genes. (a) Superoxide production as revealed by dihydroethidium staining in interstitial regions of the LV myocardium of DS/lean and DS/obese rats at 15 weeks of age. Scale bars, 100 μm. (b) Dihydroethidium fluorescence intensity determined from sections similar to those in (a). Data are expressed as the relative differences compared with DS/lean rats. (c) NADPH-dependent superoxide production in LV homogenates of DS/lean and DS/obese rats at 15 weeks of age. Results are expressed as relative light units (RLU) per mg of protein. (d–h) Quantitative real-time (RT) PCR analysis of p22^phox, gp91^phox, p47^phox, p67^phox and Rac1 mRNAs in the left ventricle of DS/lean and DS/obese rats at 15 weeks of age, respectively. The amount of each mRNA was normalized by that of 18S rRNA and then expressed relative to the mean value for DS/lean rats. Data in (b) through (h) are means±s.e.m. for surviving animals (n=10 and 14 for DS/lean and DS/obese rats, respectively). ^*P<0.05 vs. DS/lean rats.