Characterization of hypothermic intestinal ischemia-reperfusion injury in dogs. Effects of glycine.
Characterization of hypothermic intestinal ischemia-reperfusion injury in dogs. Effects of glycine.
复制标题
狗低温肠道缺血再灌注损伤的特征。
DOI：
10.1097/00007890-199607270-00005
复制
发表时间：
1996
期刊：
影响因子：
6.2
通讯作者：
Mangino,MJ
中科院分区：
文献类型：
--
作者：
Mangino,JE;Kotadia,B;Mangino,MJ
用柯林斯冲洗液单独或与假定的细胞保护剂氨基酸甘氨酸一起，研究了48小时低温（4 ℃）缺血和短期再灌注（IR）对狗肠功能和代谢的影响。低温缺血后，柯林斯冲洗段肠血流量在再灌注时短暂上升，5分钟后迅速下降，并在60分钟的再灌注期达到稳定。用5 mM甘氨酸冲洗的成对肠段在再灌注期间表现出血流量的平行变化，但相对于柯林斯段，血流量值显著更高（100-300%）。再灌注后肠耗氧量（VO 2）始终约为正常非缺血肠段的50%。相对于成对的对照肠，甘氨酸冲洗的肠段显著地消耗了约100%的氧气。肠腔的液体和蛋白质流量显着增加后IR在甘氨酸和柯林斯冲洗段。粘液组织髓过氧化物酶（MPO）活性，中性粒细胞的生化标志物，显着增加后48小时的冷缺血与柯林斯冲洗和1小时的再灌注，相对于缺血前获得的组织。再灌注诱导的MPO活性的增加被取消在肠段冲洗甘氨酸。化学引诱物白三烯B 4（LTB 4）的粘液合成在IR后显著增加，甘氨酸冲洗消除了这些增加。与非缺血组织或冷缺血无再灌注的粘膜组织相比，Collins冲洗段48小时低温缺血和1小时再灌注的粘膜组织的一氧化氮合成显著升高。甘氨酸冲洗没有改变这种模式的NO合成。在柯林斯和甘氨酸冲洗段的光镜分析表明，肠低温缺血和再灌注引起的绒毛上皮细胞的损失，绒毛高度降低，静脉充血的特点是显着的形态学变化。这些数据表明，甘氨酸显着改善氧合低温缺血和再灌注后，防止IR诱导的组织中性粒细胞浸润和白三烯合成的增加。
The effects of 48 hr of hypothermic (4 C) ischemia and short-term reperfusion (IR) on intestinal function and metabolism were studied in dogs utilizing Collins flush alone or with the putative cytoprotectant amino acid, glycine. Intestinal blood flow after hypothermic ischemia in Collins-flushed segments briefly rose at reperfusion, rapidly declined after 5 min, and plateaued over the 60-minute reperfusion period. Paired intestinal segments flushed with 5 mM glycine demonstrated parallel changes in blood flow over the reperfusion period, but the blood flow values were significantly higher (100-300%), relative to the Collins segments. Intestinal oxygen consumption (VO 2) was about 50% of normal nonischemic intestinal segments at all times after reperfusion. The glycine-flushed intestinal segments significantly consumed about 100% more oxygen, relative to the paired control intestines. Intestinal fluid and protein flux into the lumen significantly increased after IR in both glycine-and Collins-flushed segments. Mucosal tissue myeloperoxidase (MPO) activity, a biochemical marker of neutrophils, significantly increased after 48 hr of cold ischemia with Collins flush and 1 hr of reperfusion, relative to tissue obtained before ischemia. The reperfusion-induced increase in MPO activity was abolished in intestinal segments flushed with glycine. Mucosal synthesis of the chemoattractant leukotriene B 4 (LTB 4) significantly increased after IR and glycine flush abolished these increases. Nitric oxide synthesis by mucosal tissue in Collins-flushed segments subjected to 48 hr of hypothermic ischemia and 1 hr of reperfusion was significantly higher, compared with nonischemic tissue or mucosal tissue subjected to cold ischemia without reperfusion. Glycine flush did not alter this pattern of NO synthesis. Light microscopic analysis in both Collins-and glycine-flushed segments revealed that intestinal hypothermic ischemia and reperfusion caused significant morphologic changes characterized by loss of villus epithelium, decreased villus height, and venous congestion. These data indicate that glycine significantly improved oxygenation after hypothermic ischemia and reperfusion and prevented the IR-induced increase in tissue neutrophil infiltration and leukotriene synthesis.