کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2536631 | 1559155 | 2007 | 8 صفحه PDF | دانلود رایگان |
Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) inhibitor recognized as an independent risk factor for endothelial dysfunction and coronary heart diseases. This study investigated whether ADMA (10 mg/kg day for 14 days) affected endothelial function and aggravated post-ischemic ventricular dysfunction in the perfused rat heart. Systolic blood pressure and heart rate, plasma levels of ADMA and nitrite/nitrate were measured in vehicle- and ADMA-treated rats. Perfused hearts were submitted to global ischemia–reperfusion and vascular endothelial dysfunction was examined with angiotensin II in coronary vessels and aortic rings. Endothelial NO synthase (eNOS) and angiotensin-converting enzyme (ACE) mRNA expression in aortic and cardiac tissues were measured. ADMA-treated rats had higher systolic blood pressure (1.3-fold, P < 0.01) and slower heart rate (16%, P < 0.05) than controls. Plasma ADMA rose (1.9-fold, P < 0.01) and nitrite/nitrate concentration decreased 59% (P < 0.001). Ventricular contraction (stiffness) increased significantly, with worsening of post-ischemic ventricular dysfunction. In preparations from ADMA-treated rats the coronary vasculature's response to angiotensin II was almost doubled (P < 0.01) and the maximal vasorelaxant effect of acetylcholine in aortic rings was significantly lower than in preparations from vehicle-treated rats. In cardiac and aortic tissues eNOS mRNA and ACE mRNA levels were similar in controls and ADMA-treated rats. The increased plasma levels of ADMA presumably cause endothelial dysfunction because of a deficiency in NO production, which also appears involved in the aggravation of myocardial ischemia–reperfusion injury.
Journal: European Journal of Pharmacology - Volume 557, Issues 2–3, 28 February 2007, Pages 178–185