Abstract
Background: Intermittent clamping (IC) of the portal triad is an effective method of protecting the liver from ischemia-reperfusion injury (IR). In clinical practice, this method is employed during a resection, but its mechanism is still not clear.
Objectives: To evaluate the effect of IC on rat liver and determine its mechanisms.
Materials and Methods: Wistar rats were submitted to 60-min IC (cycles of 12-min clamping followed by 4-min reperfusion), and the samples were collected after 1, 6, and 72 hrs of reperfusion. We determined the serum activity of alanine aminotransferase (ALT), and measured the concentration of TNF-α, malondialdehyde (MDA) and myeloperoxidase (MPO) in liver homogenates. The apoptosis of hepatocytes was evaluated immunohistochemically.
Results: When compared to the IR rats, the activity of ALT decreased in the IC group in all periods of observation (the highest decrease of ~48% after 1 hr of reperfusion). When compared to the IR group, a statistically significant decrease (p < 0.05) in the TNF-α concentration (~33%) in the IC rats occurred only after 1 hr of reperfusion, and it was accompanied by a decrease in the MPO concentration after 1 and 6 hrs of reperfusion. IC reduces the effects of reactive oxygen species (ROS) activity, which has been confirmed by a statistically significant decrease in MDA concentration by 25%-35% in all studied periods. The limitation of hepatocytes apoptosis due to IC occurs in the early (~26%; p < 0.05) and late (~45%; p < 0.01) phases of reperfusion.
Conclusions: The use of IC in early phase of reperfusion brings about a decrease in TNF-α release, which can be related to liver injury due to neutrophil infiltration and apoptotic cell reduction. It seems that the reduction of lipid peroxidation may also limit the liver injury.
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Implication for health policy/practice/research/medical education:
Animal studies can open new windows to better understanding of pathophysiology of liver ischmia. We suggest reading this article for all pathologists. -
Please cite this paper as:
Helewski K, Kowalczyk-Ziomek G, Czecior E, Wyrobiec G, Harabin-Slowinska M, Juszko-Piekut M, et al. Protective effect of intermittent clamping of the portal triad in the rat liver on liver ischemia-reperfusion injury. Hepat Mon. 2011;11(6):445-51.
2011 Kowsar M.P.Co. All rights reserved.
Keywords
Ischemic preconditioning Acute liver failure Reperfusion injury TNF-alpha Apoptosis
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