Sevoflurane prevents liver inflammatory response induced by lung ischemia-reperfusion.

BACKGROUND: Transplants cause ischemia-reperfusion (IR) injury that can affect distant organs. Liver is particularly sensitive to IR injury. The present randomized experimental study was designed to investigate a possible protective effect of sevoflurane against liver inflammatory response to lung IR in a lung upper lobe left autotransplant model. METHODS: Two groups (sevoflurane and control) of eight swines each were submitted to upper lobe left lung autotransplant. Hypnotic maintenance was performed with sevoflurane 3% or propofol 8 to 10 mg/kg per hr until pneumonectomy was done; then propofol was used for all animals. Blood and liver samples were taken in four different moments: prepneumonectomy, prereperfusion, 10 min postreperfusion and 30 min postreperfusion to measure levels of interleukin (IL)-1ß, IL-10, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1, nuclear factor (NF)-κB, C-reactive protein, ferritin and caspase 3. Non-parametric test was used to find statistical meaning. RESULTS: Lung IR markedly increased the expression of TNF-α, IL-1ß, MCP-1, NF-κB and caspase activity in control livers compared with basal levels, whereas liver IL-10 expression decreased 10 and 30 min post-reperfusion. Sevoflurane significantly decreased TNF-α, IL-1ß, MCP-1, NF-κB liver expression and caspase 3 activity. Sevoflurane also reverted the lung IR-induced decrease in IL-10 expression. CONCLUSIONS: The present results indicate that lung IR caused hepatic injury. Sevoflurane attenuated liver injury in a model of upper lobe left lung autotransplant in pigs.

Ischaemic preconditioning prevents the liver inflammatory response to lung ischaemia/reperfusion in a swine lung autotransplant model.

OBJECTIVES: Lung ischaemia/reperfusion (IR) induces a systemic inflammatory response that causes damage to remote organs. The liver is particularly sensitive to circulating inflammatory mediators that occur after IR of remote organs. Recently, remote ischaemic preconditioning has been proposed as a surgical tool to protect several organs from IR. The present study was designed to investigate a possible protective effect of lung ischaemic preconditioning (IP) against the liver inflammatory response to lung IR. METHODS: Two groups [IP and control (CON)] of 10 Large White pigs underwent lung autotransplants (left pneumonectomy, ex situ cranial lobectomy and caudal lobe reimplantation). Before pneumonectomy was performed in the study group, IP was induced with two 5-min cycles of left pulmonary arterial occlusion and a 5-min interval of reperfusion between the two occlusions. Five animals underwent sham surgery. Liver biopsies were obtained during surgery at (i) prepneumonectomy, (ii) prereperfusion, (iii) 10 min after reperfusion of the implanted lobe and (iv) 30 min after reperfusion. The expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-10 and inducible form of nitric oxide synthase (iNOS) was analysed by western blotting. The expression of mRNA for TNF-α, IL1, IL-10, monocyte chemoattractant protein-1 (MCP-1), nuclear factor kappa beta and iNOS was analysed by reverse transcription-polymerase chain reaction. Caspase-3 activity was determined by enzyme-linked immunosorbent assay. Non-parametric tests were used to compare differences between and within groups. RESULTS: Lung IR markedly increased expression of TNF-α (P = 0.0051) and IL-1 (P = 0.0051) and caspase-3 activity (P = 0.0043) in the CON group compared with the prepneumonectomy levels. A decrease of IL-10 mRNA expression was observed in the CON group after lung reperfusion. In the IP group, TNF-α (P = 0.0011) and IL-1 (P = 0.0001) expression and caspase-3 activity (P < 0.0009) were lower after reperfusion than in the CON group. IP caused reversion of the observed decrease of IL-10 mRNA expression (P = 0.016) induced in liver tissue by lung IR. Lung IR markedly increased the expression of mRNA MCP-1 after 10 min (P = 0.0051) and 30 min (P = 0.0051) of reperfusion. These increases were not observed in the IP or sham groups. CONCLUSIONS: IP prevented liver injury induced by lung IR through the reduction of proinflammatory cytokines and hepatocyte apoptosis.

Modulation of monocyte chemoattractant protein-1 expression by ischaemic preconditioning in a lung autotransplant model.

OBJECTIVES: Monocyte chemoattractant protein-1 (MCP-1) is believed to play a crucial role in lung ischaemia-reperfusion injury (LIRI). Ischaemic preconditioning (IP) has been shown to protect several organs from ischaemia-reperfusion (IR) injury, although less is known about IP's effect on MCP-1 modulation. The objective of this study was to investigate IP's effect on MCP-1 expression in lung tissue and its relationship with oxidative stress and proinflammatory cytokine production in an experimental LIRI model. METHODS: Two groups (IP and control groups) of seven large white pigs underwent a lung autotransplant (left pneumonectomy, ex situ superior lobectomy and lower lobe reimplantation). Before pneumonectomy was performed in the study group, IP was induced with two cycles of 5 min of left pulmonary artery occlusion with a 5 min interval of reperfusion between the two occlusions. Blood samples and lung biopsies were obtained at prepneumonectomy (PPn), at prereperfusion (PRp) and up to 30 min after reperfusion of the implanted lobe (Rp-10' and Rp-30'). Haemodynamic and blood-gas measurements, evaluation of oxidative stress in lung tissue and MCP-1, tumour necrosis factor-α (TNF-α) and IL-1 protein and mRNA measurements in lung tissue were performed. Nonparametric tests were used to compare differences between groups. Data are expressed as mean ± SEM. RESULTS: In control lungs, MCP-1 protein levels were found to be higher at PRp, Rp-10' and Rp-30' than at PPn (0.59 ± 0.1 vs. 0.21 ± 0.05, 0.47 ± 0.01 vs. 0.21 ± 0.05 and 0.56 ± 0.01 vs. 0.21 ± 0.05, respectively; P < 0.05). These differences were not evident in the IP group. MCP-1 levels at PRp, Rp-10' and Rp-30' were significantly higher in the control group than in the IP group (0.59 ± 0.1 vs. 0.15 ± 0.02, 0.47 ± 0.01 vs. 0.13 ± 0.01 and 0.56 ± 0.01 vs. 0.27 ± 0.01, respectively; P < 0.05). MCP-1, TNF-α and IL-1 mRNA expressions were lower at PRp, Rp-10' and Rp-30' (control vs. IP group, P < 0.05) when IP was carried out. Lipid peroxidation metabolites and myeloperoxidase activity increase in lung tissue were prevented by IP. CONCLUSIONS: In this model, LIRI induced the expression of MCP-1 and the proinflammatory proteins TNF-α and IL-1 in control lungs. IP significantly reduced the expression of these chemokines and cytokines. These features may explain the reduction of oxidative stress observed with IP.