Similar protective effect of ischaemic and ozone oxidative preconditionings in liver ischaemia/reperfusion injury
Similar protective effect of ischaemic and ozone oxidative preconditionings in liver ischaemia/reperfusion injury
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DOI：
10.1006/phrs.2002.0952
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发表时间：
2002-04-01
影响因子：
9.3
通讯作者：
Leon, OS
中科院分区：
文献类型：
--
作者：
Ajamieh, H;Merino, N;Leon, OS
许多研究表明，肝脏再氧化后氧自由基的形成可能引发肝细胞损伤的级联反应。研究表明，臭氧控制可以促进氧化预处理或对氧化应激的适应，防止活性氧（ROS）引起的损伤，并保护肝脏免受缺血再灌注（I/R）损伤。在这些结果的基础上，我们假设在我们的实验条件下臭氧处理具有类似于缺血预处理（IscheP）机制的生化参数。四组大鼠分为：(1)假手术动物，麻醉开腹加手术手法；(2) I/R动物右肝缺血90 min，再灌注90 min；(3) I/R期前IscheP（同2组）：动物缺血10 min，再灌注10 min；(4)臭氧氧化预处理（OzoneOP），在I/R期之前（如2组）：动物通过直肠注入臭氧1 mg kg（-1）。大鼠接受15次臭氧处理，每天1次，剂量为5-5.5 ml，臭氧浓度为50马克杯ml（-1）。测定以下参数：血清转氨酶（AST、ALT）和5′-核苷酸酶（5′-NT），并以形态学测定作为肝细胞损伤指标；参与黄嘌呤脱氢酶（XDH）转化为黄嘌呤氧化酶（XO）的总巯基、钙水平和钙蛋白酶活性（分别为可逆和不可逆形式）；XO活性和丙二醛+ 4-羟基醛作为氧化应激增加的指标。与I/R组（200 +/- 22和117 +/- 21.7 U l(-1)）相比，IscheP的AST、ALT水平（130 +/- 11.4和75 +/- 5.7 U l(-1)）有所降低，而OzoneOP的酶活性（89.5 +/- 12.6和43.7 +/- 10 U l(-1)）与假手术组（63.95 +/- 11和19.48 +/- 3.2 U l(-1)）保持不变，差异无统计学意义（P < 0.05）。观察了两种预处理条件对总巯基（IscheP: 6.28 +/- 0.07, OzoneOP: 6.34 +/- 0.07/mumol mg prot(-1)）、钙浓度（IscheP: 0.18 +/- 0.09, OzoneOP: 0.20 +/- 0.06 mumol mg prot(-1)）和钙蛋白酶活性（IscheP: 1.04 +/- 0.58, OzoneOP: 1.41 +/- 0.79 U mg prot(-1)）保存的保护作用。这两种预处理都减弱了与I/R损伤相关的总XO的增加。IscheP和OzoneOP可阻止丙二醛+ 4羟基醛的生成，两种保护方法之间无统计学差异。这些结果提供了证据，这两种预处理设置在所测参数中具有相似的生化保护机制。虽然从生化角度来看，缺血和OzoneOPs之间没有差异，但组织学结果表明，在我们的实验条件下，OzoneOP比IscheP更有效地保护细胞。(C) 2002年Elsevier Science Ltd.出版
Many studies indicate that oxygen free-radical formation after reoxygenation of liver may initiate the cascade of hepatocellular injury. It has been demonstrated that controlled ozone administration may promote an oxidative preconditioning or adaptation to oxidative stress, preventing the damage induced by reactive oxygen species (ROS) and protecting against liver ischaemia-reperfusion (I/R) injury. On the basis of those results we postulated that ozone treatment in our experimental conditions has biochemical parameters similar to the ischaemic preconditioning (IscheP) mechanism. Four groups of rats were classified as follows: (1) sham-operated animals subjected to anaesthesia and laparotomy, plus surgical manipulation; (2) I/R animals were subjected to 90 min of right-lobe hepatic ischaemia, followed by 90 min of reperfusion; (3) IscheP, previous to the I/R period (as in group 2): animals were subjected to 10 min of ischaemia and 10 min of reperfusion; (4) ozone oxidative preconditioning (OzoneOP), previous to the I/R period (as in group 2): animals were treated with ozone by rectal insufflation 1 mg kg(-1). The rats received 15 ozone treatments, one per day, of 5-5.5 ml at the ozone concentration of 50 mug ml(-1). The following parameters were measured: serum transaminases (AST. ALT) and 5'-nucleotidase (5'-NT), with morphological determinations, as indicators or hepatocellular injury; total sulfhydryl groups, calcium levels and calpain activity as mediators which take part in xanthine deshydrogenase (XDH) conversion to xanthine oxidase (XO) (reversible and irreversible forms, respectively); XO activities and malondialdehyde + 4-hydroyalkenals as indicators of increased oxidative stress. AST, ALT levels were attenuated in the IscheP (130 +/- 11.4 and 75 +/- 5.7 U l(-1)) with regard to the I/R group (200 +/- 22 and 117 +/- 21.7 U l(-1)) while the OzoneOP maintained both of the enzyme activities (89.5 +/- 12.6 and 43.7 +/- 10 U l(-1)) without statistical differences (P < 0.05) in comparison with the sham-operated (63.95 +/- 11 and 19.48 +/- 3.2 U l(-1)). Protective effects of both the preconditioning settings on the preservation of total sylfhydryl groups (IscheP: 6.28 +/- 0.07, OzoneOP: 6.34 +/- 0.07/mumol mg prot(-1)), calcium concentrations (IscheP: 0.18 +/- 0.09, OzoneOP: 0.20 +/- 0.06 mumol mg prot(-1)), and calpain activity (IscheP: 1.04 +/- 0.58, OzoneOP: 1.41 +/- 0.79 U mg prot(-1)) were observed. Both of the preconditionings attenuated the increase of total XO associated to I/R injury. Generation of malondialdehyde + 4 hydroxyalkenals was prevented by IscheP and OzoneOP without statistical differences between the two protective procedures. These results provide evidence that both of the preconditioning settings share similar biochemical mechanisms of protection in the parameters which were measured. Although there were no differences from a biochemical point of view between Ischaemic and OzoneOPs, the histological results showed a more effective protection of OzoneOP than IscheP in our experimental conditions. (C) 2002 Published by Elsevier Science Ltd.