Expression and activity of superoxide dismutases in chagasic mice.

<p>C57BL/6 (WT and MnSOD^+/-) mice were infected with <i>Trypanosoma cruzi</i> (10,000 <i>Tc</i>/mouse), and sacrificed at 150 days’ post-infection (pi) corresponding to chronic disease phase. <b>(A)</b> Total DNA was used as template for genotyping the MnSOD^+/- (vs. WT) mice. The amplification of a 229 bp band indicates the integration of xx within <i>MnSOD</i> gene <b>(B-D)</b> Reverse transcription—quantitative PCR (RT-qPCR) evaluation of myocardial levels of <i>SOD1</i> <b><i>(B)</i></b>, <i>SOD2</i> <b><i>(C)</i></b> <i>and SOD3</i> <b><i>(D)</i></b> mRNAs was performed in WT and MnSOD^+/- mice before infection and at 150 days pi. The data were normalized to <i>GAPDH</i> mRNA (n = 6 mice per group, triplicate observations per mouse). <b>(E&F)</b> Representative Western blot images for myocardial levels of MnSOD and GAPDH (loading control) are shown (<b><i>E</i></b>, n = 3 mice per group). Densitometry analysis was performed for Western blot gels representing n = 6 mice per group (duplicate observations per mouse), and data were normalized to GAPDH levels <b><i>(F)</i></b>. <b>(G)</b> Heart homogenates were subjected to differential centrifugation to isolate mitochondria. Mitochondrial MnSOD activity was determined by a spectrophotometric assay (n = 6 mice per group, duplicate observations per mouse). Data in bar graphs are plotted as mean value ± SEM. Statistical significance are marked as ^aMnSOD^+/- vs. WT, ^bWT.<i>Tc</i> vs. WT, ^cMnSOD^+/-.<i>Tc</i> vs. MnSOD^+/-, ^dMnSOD^+/-.<i>Tc</i> vs. WT.<i>Tc</i>, and ^eMnSOD^+/-.<i>Tc</i> vs. WT (p value < 0.05).