Zahler Stefan, Heindl Bernhard, Becker Bernhard F
Department of Physiology, Ludwig Maximilians University, Schillerstr 44, 80336 Munich, Germany.
Basic Res Cardiol. 2002 Sep;97(5):359-64. doi: 10.1007/s00395-002-0369-4.
Neutrophil adhesion to coronary endothelium is a key event for cardiac reperfusion injury. Adhesion is proposed to be a multi-step event, consisting of selectin-mediated rolling, chemotactic activation, and subsequent integrin-mediated firm attachment. However, it is not clear whether this sequence also occurs in the coronary circulation with its unique hemodynamic properties (turbulent flow, flow reversal). We have studied neutrophil adhesion in the coronary system of isolated perfused guinea pig hearts under basal and reperfusion conditions (15 min global ischemia). Adhesion was manipulated by an anti-CD18 antibody (blocking firm adhesion) and fucoidin (reducing rolling). Neutrophil behavior during coronary passage was assessed by measurement of CD11b expression, forward scatter (FSC, indicating polarization), and sideward scatter (SSC, measure for granularity) via flow cytometry. Adhesion rose from 21 % (basal) to 35 % after ischemia. Anti-CD18 decreased adhesion to 11 % and 14 %, respectively; fucoidin altered only the postischemic increase (23 %). CD11b was unchanged by passage through the non-ischemic coronaries, but rose postischemically (139 % increase). CD18 blockade did not reduce the postischemic rise of CD11b, while fucoidin was inhibitory (24 % increase). FSC did not differ between controls and ischemic hearts in any group, while SSC decreased most in postischemic hearts after CD18 blockade. Blockade of rolling and of firm attachment both reduce neutrophil retention, while only inhibition of rolling reduces intracoronary activation. Thus, rolling seems to be mandatory for endothelial-leukocyte communication in the coronary system.
中性粒细胞与冠状动脉内皮的黏附是心脏再灌注损伤的关键事件。黏附被认为是一个多步骤过程，包括选择素介导的滚动、趋化激活以及随后整合素介导的牢固黏附。然而，尚不清楚在具有独特血流动力学特性（湍流、血流逆转）的冠状动脉循环中是否也会发生这一序列过程。我们研究了在基础状态和再灌注条件下（15分钟全心缺血），分离灌注的豚鼠心脏冠状动脉系统中的中性粒细胞黏附情况。通过抗CD18抗体（阻断牢固黏附）和岩藻依聚糖（减少滚动）来控制黏附。通过流式细胞术测量CD11b表达、前向散射（FSC，指示极化）和侧向散射（SSC，颗粒度测量）来评估中性粒细胞在冠状动脉通过过程中的行为。缺血后黏附率从21%（基础状态）升至35%。抗CD18分别将黏附率降至11%和14%；岩藻依聚糖仅改变缺血后的增加情况（增加23%）。通过非缺血冠状动脉时CD11b无变化，但缺血后升高（增加139%）。CD18阻断并未降低缺血后CD11b的升高，而岩藻依聚糖具有抑制作用（增加24%）。任何组中对照组和缺血心脏之间FSC均无差异，而CD18阻断后缺血心脏中SSC下降最为明显。阻断滚动和牢固黏附均会减少中性粒细胞滞留，而只有抑制滚动会降低冠状动脉内的激活。因此，在冠状动脉系统中，滚动似乎是内皮细胞与白细胞通讯所必需的。
