Daiber Andreas, Münzel Thomas
The 2nd Medical Clinic, Medical Center of the Johannes Gutenberg University , Mainz, Germany .
Antioxid Redox Signal. 2015 Oct 10;23(11):899-942. doi: 10.1089/ars.2015.6376. Epub 2015 Sep 24.
Organic nitrates, such as nitroglycerin (GTN), isosorbide-5-mononitrate and isosorbide dinitrate, and pentaerithrityl tetranitrate (PETN), when given acutely, have potent vasodilator effects improving symptoms in patients with acute and chronic congestive heart failure, stable coronary artery disease, acute coronary syndromes, or arterial hypertension. The mechanisms underlying vasodilation include the release of •NO or a related compound in response to intracellular bioactivation (for GTN, the mitochondrial aldehyde dehydrogenase [ALDH-2]) and activation of the enzyme, soluble guanylyl cyclase. Increasing cyclic guanosine-3',-5'-monophosphate (cGMP) levels lead to an activation of the cGMP-dependent kinase I, thereby causing the relaxation of the vascular smooth muscle by decreasing intracellular calcium concentrations. The hemodynamic and anti-ischemic effects of organic nitrates are rapidly lost upon long-term (low-dose) administration due to the rapid development of tolerance and endothelial dysfunction, which is in most cases linked to increased intracellular oxidative stress. Enzymatic sources of reactive oxygen species under nitrate therapy include mitochondria, NADPH oxidases, and an uncoupled •NO synthase. Acute high-dose challenges with organic nitrates cause a similar loss of potency (tachyphylaxis), but with distinct pathomechanism. The differences among organic nitrates are highlighted regarding their potency to induce oxidative stress and subsequent tolerance and endothelial dysfunction. We also address pleiotropic effects of organic nitrates, for example, their capacity to stimulate antioxidant pathways like those demonstrated for PETN, all of which may prevent adverse effects in response to long-term therapy. Based on these considerations, we will discuss and present some preclinical data on how the nitrate of the future should be designed.
有机硝酸盐,如硝酸甘油(GTN)、5-单硝酸异山梨酯、二硝酸异山梨酯和戊四硝酯(PETN),急性给药时具有强大的血管舒张作用,可改善急性和慢性充血性心力衰竭、稳定型冠状动脉疾病、急性冠状动脉综合征或动脉高血压患者的症状。血管舒张的潜在机制包括响应细胞内生物活化(对于GTN,为线粒体醛脱氢酶[ALDH-2])释放•NO或相关化合物以及激活可溶性鸟苷酸环化酶。环磷酸鸟苷(cGMP)水平升高会导致cGMP依赖性激酶I激活,从而通过降低细胞内钙浓度使血管平滑肌松弛。由于耐受性和内皮功能障碍的迅速发展,长期(低剂量)给药后有机硝酸盐的血流动力学和抗缺血作用会迅速丧失,在大多数情况下,这与细胞内氧化应激增加有关。硝酸盐治疗下活性氧的酶源包括线粒体、NADPH氧化酶和未偶联的•NO合酶。有机硝酸盐的急性高剂量激发会导致类似的效力丧失(快速耐受性),但病理机制不同。有机硝酸盐之间的差异在诱导氧化应激以及随后的耐受性和内皮功能障碍的能力方面得到了突出体现。我们还讨论了有机硝酸盐的多效性作用,例如它们刺激抗氧化途径的能力,如PETN所显示的那样,所有这些都可能预防长期治疗的不良反应。基于这些考虑,我们将讨论并展示一些关于未来硝酸盐应如何设计的临床前数据。