Use of a hanging-weight system for liver ischemic preconditioning in mice

Abstract

Hart ML, Much C, Kö hler D, Schittenhelm J, Gorzolla IC, Stahl GL, Eltzschig HK. Use of a hanging-weight system for liver ischemic preconditioning in mice. Am J Physiol Gastrointest Liver Physiol 294: G1431-G1440, 2008. First published April 24, 2008 doi:10.1152/ajpgi.00083.2008 represents a powerful experimental strategy to identify novel molecular targets to attenuate hepatic injury during ischemia. As a result, murine studies of hepatic IP have become an important field of research. However, murine IP is technically challenging, and experimental details can alter the results. Therefore, we systematically tested a novel model of hepatic IP by using a hanging-weight system for portal triad occlusion. This system has the benefit of applying intermittent hepatic ischemia and reperfusion without manipulation of a surgical clamp or suture, thus minimizing surgical trauma. Systematic evaluation of this model revealed a close correlation of hepatic ischemia time with liver damage as measured by alanine (ALT) and aspartate (AST) aminotransferase serum levels. Using different numbers of IP cycles and times intervals, we found optimal liver protection with four cycles of 3 min ischemia/3 min reperfusion as measured by ALT, AST, lactate dehydrogenase, and interleukin-6. Similarly, ischemiaassociated increases in hepatic infarct size, neutrophil infiltration, and histological injury were maximally attenuated with the above regimen. To demonstrate transcriptional consequences of liver IP, we isolated RNA from preconditioned liver and confirmed transcriptional modulation of known target genes (equilibrative nucleoside transporters, acute-phase complement genes). Taken together, these studies confirm highly reproducible liver injury and protection by IP when using the hanging-weight system for hepatic ischemia and intermittent reperfusion. Further studies of murine IP may consider this technique.

Intravital multiphoton microscopy can model uptake and excretion of fluorescein in hepatic ischemia-reperfusion injury

“…15,16 During liver transplantation, ischemic damage occurs when blood flow is cut off to the donating liver, and the injury is further intensified when the liver is transplanted into the recipient. 17 The reason for reperfusion injury is the reintroduction of oxygenated blood, which results in oxidative stress, causing increased microvascular permeability, intracellular ATP loss, inflammatory cell infiltration, and, potentially, cell death.…”

Multiphoton microscopy can visualize zonal damage and decreased cellular metabolic activity in hepatic ischemia-reperfusion injury in rats

“…3 During orthotopic liver transplantation, oxygenated blood is reintroduced to the liver resulting in oxidative stress through free radical production. 4 Hepatic injury in the transplanted liver results in intracellular adenosine triphosphate (ATP) loss, increased microvascular permeability, inflammatory cell infiltration, and potentially, cell death in the forms of apoptosis and necrosis.…”

Use of a Hanging-weight System for Liver Ischemia in Mice

“…As a result, procedures like pre-conditioning, with short times of ischemia and reperfusion, can be easily performed. Systematic evaluation of this model by performing different ischemia and reperfusion times revealed a close correlation of hepatic ischemia time with liver damage as measured by alanine (ALT) and aspartate (AST) aminotransferase serum levels 3,9 . Taken together, these studies confirm highly reproducible liver injury when using the hanging-weight system for hepatic ischemia and intermittent reperfusion.…”

“…liver transplantation, hepatic tumor resection or trauma repair and can result in liver failure which has a high mortality rate [1][2] . Therefore murine studies of hepatic ischemia have become an important field of research by providing the opportunity to utilize pharmacological and genetic studies [3][4][5][6][7][8][9] . Specifically, conditional mice with tissue specific deletion of a gene (cre, flox system) provide insights into the role of proteins in particular tissues [10][11][12][13] .…”

“…Specifically, conditional mice with tissue specific deletion of a gene (cre, flox system) provide insights into the role of proteins in particular tissues [10][11][12][13] . Because of the technical difficulty associated with manually clamping the portal triad in mice, we performed a systematic evaluation using a hanging-weight system for portal triad occlusion which has been previously described 3 . By using a hanging-weight system we place a suture around the left branch of the portal triad without causing any damage to the hepatic lobes, since also the finest clamps available can cause hepatic tissue damage because of the close location of liver tissue to the vessels.…”