Hartmann Petra, Fet Ngwi, Garab Dénes, Szabó Andrea, Kaszaki József, Srinivasan Pramod Kadaba, Tolba René H, Boros Mihály
Institute of Surgical Research, University of Szeged, Szeged, Hungary.
Institute of Laboratory Animal Science and Experimental Surgery, RWTH Aachen University, Aachen, Germany.
J Surg Res. 2014 Jun 1;189(1):32-40. doi: 10.1016/j.jss.2013.12.025. Epub 2014 Jan 3.
We set out to investigate the microcirculatory consequences of hepatic ischemia-reperfusion (IR) injury and the effects of L-alpha-glycerylphosphorylcholine (GPC), a deacylated phospholipid derivative, on postischemic hepatocellular damage, with special emphasis on the expression of nicotinamide adenine dinucleotide phosphate oxidase type 4 (NOX4), which is predominantly expressed in hepatic microvessels.
Anesthetized male Sprague-Dawley rats were subjected to 60-min ischemia of the left liver lobes and 180-min reperfusion, with or without GPC treatment (50 mg/kg intravenously 5 min before reperfusion, n = 6 each). A third group (n = 6) served as saline-treated control. Noninvasive online examination of the hepatic microcirculation was performed hourly by means of modified spectrometry. Plasma tumor necrosis factor (TNF-α), high-mobility group box 1 protein (HMGB1), plasma aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels, tissue xanthine oxidoreductase (XOR) and myeloperoxidase (MPO) activities, and expressions of NOX2 and NOX4 proteins were determined.
Liver IR resulted in significant increases in NOX2 and NOX4 expressions and XOR and MPO activities, and approximately 2-fold increases in the levels of the inflammatory cytokines TNF-α and HMGB1. The microvascular blood flow and tissue oxygen saturation decreased by ∼20% from control values. GPC administration ameliorated the postischemic microcirculatory deterioration and reduced the liver necroenzyme levels significantly; the NOX4 expression, MPO activity, and HMGB1 level were also decreased, whereas the NOX2 expression, TNF-α level, and XOR activity were not influenced by GPC pretreatment.
NOX4 activation is a decisive component in the IR-induced microcirculatory dysfunction. Exogenous GPC ameliorates the inflammatory activation, and preserves the postischemic microvascular perfusion and liver functions, these effects being associated with a reduced hepatic expression of NOX4.
我们旨在研究肝脏缺血再灌注（IR）损伤的微循环后果，以及脱酰磷脂衍生物L-α-甘油磷酸胆碱（GPC）对缺血后肝细胞损伤的影响，特别关注主要在肝微血管中表达的烟酰胺腺嘌呤二核苷酸磷酸氧化酶4（NOX4）的表达。
将麻醉后的雄性Sprague-Dawley大鼠左肝叶进行60分钟缺血和180分钟再灌注，分为接受或不接受GPC治疗（再灌注前5分钟静脉注射50mg/kg，每组n = 6）。第三组（n = 6）作为生理盐水处理的对照。通过改良光谱法每小时对肝脏微循环进行无创在线检查。测定血浆肿瘤坏死因子（TNF-α）、高迁移率族蛋白B1（HMGB1）、血浆天冬氨酸转氨酶、丙氨酸转氨酶和乳酸脱氢酶水平、组织黄嘌呤氧化还原酶（XOR）和髓过氧化物酶（MPO）活性以及NOX2和NOX4蛋白的表达。
肝脏IR导致NOX2和NOX4表达以及XOR和MPO活性显著增加，炎症细胞因子TNF-α和HMGB1水平增加约2倍。微血管血流量和组织氧饱和度较对照值降低约20%。给予GPC改善了缺血后微循环恶化并显著降低了肝脏坏死酶水平；NOX4表达、MPO活性和HMGB1水平也降低，而NOX2表达、TNF-α水平和XOR活性不受GPC预处理影响。
NOX4激活是IR诱导的微循环功能障碍的决定性因素。外源性GPC改善炎症激活，保留缺血后微血管灌注和肝功能，这些作用与肝脏中NOX4表达降低有关。
