Lefer D J, Scalia R, Campbell B, Nossuli T, Hayward R, Salamon M, Grayson J, Lefer A M
Department of Medicine, Cardiology Section, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
J Clin Invest. 1997 Feb 15;99(4):684-91. doi: 10.1172/JCI119212.
Peroxynitrite (ONOO-) anion, formed by the interaction of superoxide with nitric oxide (NO), has previously been implicated as a cytotoxic agent. However, the effects of this free radical species on neutrophil (PMN)-endothelial cell interactions is largely unknown. We investigated the direct actions of ONOO- on PMN adhesion to endothelial cells in vitro and in vivo, as well as the effects of ONOO- on PMN-mediated myocardial ischemia-reperfusion injury. In vitro, peroxynitrite (100-1,000 nM) inhibited the adhesion of rat PMNs to the endothelium of isolated thrombin- or H2O2-stimulated rat mesenteric artery (P < 0.01 vs. thrombin or H2O2 alone). In vivo, in the rat mesentery, thrombin (0.5 U/ml) or N(G)-nitro-L-arginine-methyl ester (50 microM) significantly increased venular leukocyte rolling and adherence, which were also significantly (P < 0.01) attenuated by ONOO (800 nM) accompanied by reduced P-selectin expression on the endothelial cell surface. Isolated perfused rat hearts were subjected to global ischemia and reperfusion with rat PMNs (10(8) cells), which resulted in profound cardiac depression (i.e., a marked reduction in left ventricular developed pressure and maximal rate of development of left ventricular pressure). Infusion of ONOO- reversed the myocardial contractile dysfunction of ischemic-reperfused rat hearts to near baseline levels, and markedly attenuated the accumulation of PMNs in the postischemic heart. The present study provides strong evidence that nanomolar concentrations of ONOO- both inhibit leukocyte-endothelial cell interactions and exert cytoprotective effects in myocardial ischemia-reperfusion injury. Furthermore, our results suggest that the inhibition of P-selectin expression by peroxynitrite is a key mechanism of the modulatory actions of ONOO- on leukocyte-endothelial cell interactions.
过氧亚硝酸盐（ONOO⁻）阴离子由超氧化物与一氧化氮（NO）相互作用形成，此前被认为是一种细胞毒性剂。然而，这种自由基对中性粒细胞（PMN）与内皮细胞相互作用的影响在很大程度上尚不清楚。我们研究了ONOO⁻对体外和体内PMN与内皮细胞黏附的直接作用，以及ONOO⁻对PMN介导的心肌缺血-再灌注损伤的影响。在体外，过氧亚硝酸盐（100 - 1000 nM）抑制大鼠PMN与分离的经凝血酶或H₂O₂刺激的大鼠肠系膜动脉内皮的黏附（与单独的凝血酶或H₂O₂相比，P < 0.01）。在体内，在大鼠肠系膜中，凝血酶（0.5 U/ml）或N⁺-硝基-L-精氨酸甲酯（50 μM）显著增加小静脉白细胞滚动和黏附，而ONOO⁻（800 nM）也显著（P < 0.01）减弱了这种现象，同时内皮细胞表面P-选择素表达降低。分离的灌注大鼠心脏经历整体缺血和再灌注，并加入大鼠PMN（10⁸个细胞），这导致严重的心脏抑制（即左心室舒张末压和左心室压力最大上升速率显著降低）。注入ONOO⁻可将缺血-再灌注大鼠心脏的心肌收缩功能障碍逆转至接近基线水平，并显著减轻缺血后心脏中PMN的积聚。本研究提供了有力证据，表明纳摩尔浓度的ONOO⁻既能抑制白细胞与内皮细胞的相互作用，又能在心肌缺血-再灌注损伤中发挥细胞保护作用。此外，我们的结果表明，过氧亚硝酸盐对P-选择素表达的抑制是ONOO⁻对白细胞与内皮细胞相互作用调节作用的关键机制。
