Reperfusion does not induce oxidative stress but sustained endoplasmic reticulum stress in livers of rats subjected to traumatic-hemorrhagic shock.

Abstract

Oxidative stress is believed to accompany reperfusion and to mediate dysfunction of the liver after traumatic-hemorrhagic shock (THS). Recently, endoplasmic reticulum (ER) stress has been suggested as an additional factor. This study investigated whether reperfusion after THS leads to increased oxidative and/or ER stress in the liver. In a rat model, including laparotomy, bleeding until decompensation, followed by inadequate or adequate reperfusion phase, three time points were investigated: 40 min, 3 h, and 18 h after shock. The reactive oxygen and nitrogen species and its scavenging capacity (superoxide dismutase 2), the nitrotyrosine formation in proteins, and the lipid peroxidation together with the status of endogenous antioxidants (alpha-tocopherylquinone-alpha-tocopherol ratio) were investigated as markers for oxidative or nitrosylative stress. Mitochondrial function and cytochrome P450 isoform 1A1 activity were analyzed as representatives for hepatocyte function. Activation of the inositol-requiring enzyme 1/X-box binding protein pathway and up-regulation of the 78-kDa glucose-regulated protein were recorded as ER stress markers. Plasma levels of alanine aminotransferase and Bax/Bcl-XL messenger RNA (mRNA) ratio were used as indicators for hepatocyte damage and apoptosis induction. Oxidative or nitrosylative stress markers or representatives of hepatocyte function were unchanged during and short after reperfusion (40 min, 3 h after shock). In contrast, ER stress markers were elevated and paralleled those of hepatocyte damage. Incidence for sustained ER stress and subsequent apoptosis induction were found at 18 h after shock. Thus, THS or reperfusion induces early and persistent ER stress of the liver, independent of oxidative or nitrosylative stress. Although ER stress was not associated with depressed hepatocyte function, it may act as an early trigger of protracted cell death, thereby contributing to delayed organ failure after THS.

• Authors: Johanna Catharina Duvigneau, Andrey V Kozlov, Clara Zifko, Astrid Postl, Romana T Hartl, Ingrid Miller, Lars Gille, Katrin Staniek, Rudolf Moldzio, Wolfgang Gregor, Susanne Haindl, Tricia Behling, Heinz Redl, Soheyl Bahrami
• Journal: Shock (Augusta, Ga.) (Shock) Vol. 33 Issue 3 Pg. 289-98 (Mar 2010) ISSN: 1540-0514 [Electronic] United States
• PMID: 19503022 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA-Binding Proteins
• GRP78 protein, rat
• Heat-Shock Proteins
• Reactive Nitrogen Species
• Regulatory Factor X Transcription Factors
• Transcription Factors

Topics

• Acute Lung Injury (pathology)
• Animals
• Apoptosis (physiology)
• DNA-Binding Proteins (metabolism)
• Endoplasmic Reticulum (metabolism)
• Heat-Shock Proteins (metabolism)
• Male
• Mitochondria, Liver (physiology)
• Oxidative Stress (physiology)
• Rats
• Rats, Sprague-Dawley
• Reactive Nitrogen Species (metabolism)
• Regulatory Factor X Transcription Factors
• Reperfusion
• Resuscitation
• Shock, Hemorrhagic (physiopathology)
• Shock, Traumatic (physiopathology)
• Transcription Factors (metabolism)