Serum nitrotyrosine concentration in dogs with myxomatous mitral valve disease

The aim of this study was to compare serum nitrotyrosine concentrations in healthy dogs with those in dogs with myxomatous mitral valve disease (MMVD). Fifty client-owned dogs were included in this study. Based on echocardiographic results, dogs were categorized into healthy (control), mild-, moderate-, and severe-MMVD groups. Serum nitrotyrosine concentrations were determined from enzyme-linked immunosorbent assays. No significant difference between control dogs and dogs with mild MMVD was detected (p = 0.31). However, dogs with moderate MMVD had significantly higher serum concentrations of nitrotyrosine (p = 0.04) than that in controls, and dogs with severe MMVD had significantly lower serum concentrations of nitrotyrosine (p = 0.03) than that in moderate MMVD dogs. There were negative correlations in the association of serum nitrotyrosine with age (n = 30, R²= 0.067, p = 0.27), left atrial-to-aortic root diameter ratio (n = 30, R²= 0.02, p = 0.57), and platelet count (n = 30, R²= 0.39, p = 0.003); however, only the platelet correlation was significant. Among dogs with MMVD, there was no significant difference in serum nitrotyrosine concentration between males and females. The results of this study suggest that tyrosine nitration end-products might be potential biomarkers for the detection of MMVD in dogs.

The study of susceptibility to ischemia-reperfusion injury in heart of aged rat / 中华老年医学杂志

Objective To determine whether the susceptibility to ischemia-reperfusion injury in aged heart is higher than that in adult heart and,if so,to clarify the mechanisms underlying this change.Methods Wister rats(5-or 20-month-old)were randomly divided into 4 groups(6 animals in each group).The rats were subjected to 30 minutes of myocardial ischemia via ligating the left anterior descending coronary artery,followed by 3 hours of reperfusion(Young-MI/R group and Old-MI/R group);A silk suture around the left anterior descending coronary artery was not ligated in young and old rats(Young-sham group and Old-sham group).Myocardial apoptosis was detected by terminal deoxynueleotidyl transferase biotin-d UTP nick end labeling(TUNEL)staining and caspase-3 activity was detected by using a caspase-3 colorimetrie assay.Nitrotyrosine content,a footprint of in vivo ONOO~-formation,and total NO content were determined by ELISA and chemiluminescence method respectively.Results A significantly exacerbated cardiac reperfusion injury was found in Old-MI/R group as evidenced by increased TUNEL positive myocytes[(19.0?2.1)% vs.(14.6?1.7)%],and increased myocardial caspase-3 activity[(436?35)?mool/mg vs.(340?32)?mol/mg] compared with Young-MI/R group(P＜0.05).Aged hearts had a markedly increased basal NOx level compared with young adult hearts.Marked higher myocardial nitrotyrosine content was found in OId-MI/R group[(7.25?0.18)nmol/g]than that in Young-MI/R group[(4.68?0.15)nmol/g] (P＜0.05).Conclusions In aged hearts,high levels of NO might form highly toxie derivant, ONOO~-,and its subsequent nitrified protein.This may attribute to the increased susceptibility of the aged heart to isehemic-reperfusion injury.

Effects of diabetes on ischemic/reperfusion injury and cell apoptosis in rats myocardium via alterations in peroxynitrite / 中国病理生理杂志

AIM:To determine the effects of different-term streptozotocin(STZ)-induced diabetes on ischemia/reperfusion(I/R)injury and cell apoptosis in rats myocardial via alterations in myocardial peroxynitrite.METHODS:The models of I/R injury were induced by occlusion and reperfusion of the left descending coronary artery(LDCA)in rats.I/R-induced infarct size was determined using triphenyltetrazolium chloride(TTC)staining.Quantified caspase-3 expression was used to represent apoptosis by Western blotting analysis.Peroxynitrite formation as indicated by nitrotyrosine level was measured by morphometric analysis.RESULTS:Two weeks after STZ treatment,infarct size(35.00%?3.00%)was smaller in 2 weeks diabetic hearts(2WKD)as compared with time-matched control group(2WKC)(51.00%?3.30%),whereas after 16 weeks of diabetes(16WKD),the infarct size(61.00%?3.00%)was bigger in the diabetic hearts as compared with the 16WKC group(50.00%?2.00%,P

Peroxynitrite aggravates myocardium injury in acute myocardial infarction during ischemia-reperfusion / 中国介入心脏病学杂志

Objective To investigate the changes of peroxynitrite(ONOO-)in acute myocardial infarction during ischemia-reper fusion.Methods Thirty patients with actute myocardial infarction(single coronary arterial stenosis of left anterior descending in proximal-middle segment) and twenty-four healthy cases were enrolled as the control in our research.Peripheral blood were taken at the time of 24 h and 72 h after primary percutaneous coronary intervention.The patients were further divided into 2 groups according to their serum cTnI level(mild myocardium injury group with cTnI 0.05).Conclusion Plasma peroxynitrite(ONOO-) is related to myocardium injury during ischemia-reperfusion in actue myocardial infarction which suggest that peroxynitrite may aggravate myocardium injury in acute myocardial infarction during ischemia-reperfusion.