Figure 7
From: Hyperglycemia-induced diaphragm weakness is mediated by oxidative stress
Hyperglycemia increases tyrosine nitration of several diaphragm proteins. A) is a representative blot for nitrotyrosine staining in diaphragm homogenates from control (black), hyperglycemic (red), hyperglycemic + PEG-SOD (blue), and hyperglycemic + denatured (heat inactivated) PEG-SOD animals. B) indicates mean ± SEM of the densitometric analyses for Bands 1 to 4 (n = 6 for comparisons between the four experimental groups). As shown, at least four band differences were noted between control and hyperglycemic diaphragm homogenates; administration of PEG-SOD to hyperglycemic animals largely reversed the hyperglycemia-induced changes in nitrotyrosine staining in diaphragm homogenates, suggesting that the PEG-SOD-induced reductions in superoxide generation prevented peroxynitrite formation and subsequent tyrosine nitration of proteins. These effects were not seen with administration of denatured PEG-SOD. (P <0.001, *significantly different when compared to control or hyperglycemia + PEG-SOD). PEG-SOD, polyethylene glycol superoxide dismutase; SEM, standard error of the mean.