Mechanisms of adiponectin protection against diabetes-induced vascular endothelial injury / 生理学报

The incidence and mortality rates of diabetes with cardiovascular complications are continually rising, and diabetic cardiovascular disease is becoming a major public health issue that threatens human health. Acute endothelial dysfunction and chronic cellular damage caused by diabetes are important risk factors for diabetic cardiovascular disease and related mortality. Adiponectin is an adipocyte-derived molecule with significant cytoprotective effects, including the protection against diabetes-induced vascular endothelial injury. Here we review the mechanisms of adiponectin protective effects on acute vascular endothelial dysfunction and chronic structural damage induced by diabetes.

Nitroglycerin tolerance aggravates arterial ischemia/reperfusion injury by increasing nitrotyrosine and ONOO- production / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the influence of nitroglycerin tolerance (NT) on arterial ischemia (90 min) and reperfusion (120 min).</p><p><b>METHODS</b>Male Sprague-Dawley rats were infused with nitroglycerin (GTN) or saline for 12 h and ascending aorta was rapidly isolated. The isolated aorta was subjected to one of the following treatments: stimulative ischemia/reperfusion, stimulative ischemia/reperfusion (I/R) plus glutathione (GSH, 0.1 mmol/L) during reperfusion, or control solution (Kreb's solution for 3.5 h).</p><p><b>RESULTS</b>Compared with I/R group, contractile function, vasorelaxation responses to Ach, NO production were significantly decreased and CK, LDH activity as well as nitrotyrosine formation in reperfusion solution were significantly increased in I/R + NT group and these effects could be prevented with addition of GSH in I/R + NT aortas.</p><p><b>CONCLUSIONS</b>Our results demonstrated that NT could aggravate arterial I/R injury by increasing the production of ONOO- and GSH may play a cardioprotective role against NT-induced myocardial injury by attenuating the formation of ONOO-.</p>

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.