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- Björnsson, Bergthor, et al.
(författare)
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Conventional, but not remote ischemic preconditioning, reduces iNOS transcription in liver ischemia/reperfusion
- 2014
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 20:28, s. 9506-9512
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To study the effects of preconditioning on inducible nitric oxide synthase (iNOS) and interleukin 1 (IL-1) receptor transcription in rat liver ischemia/reperfusion injury (IRI). METHODS: Seventy-two male rats were randomized into 3 groups: the one-hour segmental ischemia (IRI, n = 24) group, the ischemic preconditioning (IPC, n = 24) group or the remote ischemic preconditioning (R-IPC, n = 24) group. The IPC and R-IPC were performed as 10 min of ischemia and 10 min of reperfusion. The iNOS and the IL-1 receptor mRNA in the liver tissue was analyzed with real time PCR. The total Nitrite and Nitrate (NOx) in continuously sampled microdialysate (MD) from the liver was analyzed. In addition, the NOx levels in the serum were analyzed. RESULTS: After 4 h of reperfusion, the iNOS mRNA was significantly higher in the R-IPC (Delta Ct: 3.44 +/- 0.57) group than in the IPC (Delta Ct: 5.86 +/- 0.82) group (P = 0.025). The IL-1 receptor transcription activity was reduced in the IPC group (Delta Ct: 1.88 +/- 0.53 to 4.81 +/- 0.21), but not in the R-IPC group, during reperfusion (P = 0.027). In the MD, a significant drop in the NOx levels was noted in the R-IPC group (12.3 +/- 2.2 to 4.7 +/- 1.2 mu mol/L) at the end of ischemia compared with the levels in early ischemia (P = 0.008). A similar trend was observed in the IPC group (11.8 +/- 2.1 to 6.4 +/- 1.5 mu mol/L), although this difference was not statistically significant. The levels of NOx rose quickly during reperfusion in both groups. CONCLUSION: IPC, but not R-IPC, reduces iNOS and IL-1 receptor transcription during early reperfusion, indicating a lower inflammatory reaction. NOx is consumed in the ischemic liver lobe.
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| 2. |
- Björnsson, Bergthor, et al.
(författare)
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Nitrite, a novel method to decrease ischemia/reperfusion injury in the rat liver
- 2015
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 21:6, s. 1775-1783
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate whether nitrite administered prior to ischemia/reperfusion (I/R) reduces liver injury.METHODS: Thirty-six male Sprague-Dawley rats were randomized to 3 groups, including sham operated (n = 8), 45-min segmental ischemia of the left liver lobe (IR, n = 14) and ischemia/reperfusion (I/R) preceded by the administration of 480 nmol of nitrite (n = 14). Serum transaminases were measured after 4 h of reperfusion. Liver microdialysate (MD) was sampled in 30-min intervals and analyzed for glucose, lactate, pyruvate and glycerol as well as the total nitrite and nitrate (NOx). The NOx was measured in serum.RESULTS: Aspartate aminotransferase (AST) at the end of reperfusion was higher in the IR group than in the nitrite group (40 ± 6.8 μkat/L vs 22 ± 2.6 μkat/L, P = 0.022). Similarly, alanine aminotransferase (ALT) was also higher in the I/R group than in the nitrite group (34 ± 6 μkat vs 14 ± 1.5 μkat, P = 0.0045). The NOx in MD was significantly higher in the nitrite group than in the I/R group (10.1 ± 2.9 μM vs 3.2 ± 0.9 μM, P = 0.031) after the administration of nitrite. During ischemia, the levels decreased in both groups and then increased again during reperfusion. At the end of reperfusion, there was a tendency towards a higher NOx in the I/R group than in the nitrite group (11.6 ± 0.7 μM vs 9.2 ± 1.1 μM, P = 0.067). Lactate in MD was significantly higher in the IR group than in the nitrite group (3.37 ± 0.18 mM vs 2.8 ± 0.12 mM, P = 0.01) during ischemia and the first 30 min of reperfusion. During the same period, glycerol was also higher in the IRI group than in the nitrite group (464 ± 38 μM vs 367 ± 31 μM, P = 0.049). With respect to histology, there were more signs of tissue damage in the I/R group than in the nitrite group, and 29% of the animals in the I/R group exhibited necrosis compared with none in the nitrite group. Inducible nitric oxide synthase (iNOS) transcription increased between early ischemia (t = 15) and the end of reperfusion in both groups.CONCLUSION: Nitrite administered before liver ischemia in the rat liver reduces anaerobic metabolism and cell necrosis, which could be important in the clinical setting.
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