The Protective Effect of α-Tocopherol and GdCl3 Against Hepatic Ischemia/Reperfusion Injury

Purpose To evaluate the combined effect of α-tocopherol and gadolinium chloride (GdCl₃) in reducing lipid peroxidation after severe hepatic ischemia/reperfusion (IR) injury. Methods Sixty male Wistar rats, 200–250 g, were randomly divided into six equal groups. There were two sham operation (SHAM) groups, two untreated IR groups, and two IR groups treated with GdCl₃ and α-tocopherol (IRGT). After 60 min of total hepatic ischemia and 120 min reperfusion, one of each group was killed, liver samples were taken for malondialdehyde (MDA) and myeloperoxidase (MPO) analysis and light microscopy examination, and blood samples were analyzed for aspartate (AST) and alanine (ALT) transaminase, lactate dehydrogenase (LDH), and α-tocopherol content. The remaining groups were monitored for survival rate determination. Results The mean MDA and MPO values in the SHAM, IR, and IRGT groups, respectively, were 1.117, 1.476, and 0.978 nmol/g wet tissue and 1.49, 6.26, and 1.78 (U/g). The mean α-tocopherol values in the SHAM, IR, and IRGT groups, respectively, were 10.4, 1.9, and 12 μmol/l. The mean serum AST, ALT, and LDH values were significantly higher in the IR group than in the SHAM group (P < 0.001), and significantly lower in the IRGT group than in the IR group (P < 0.001). Light microscopy examination revealed more severe congestion and vacuolization in the IR group than in the SHAM group, and minimal congestion and vacuolization in the IRGT group. Survival was significantly higher in the IRGT group than in the IR group. Conclusion The administration of GdCl₃ and α-tocopherol is likely to protect the liver against lipid peroxidation by suppressing Kupffer cell and polymorphonuclear leukocyte activation and enhancing endogenous antioxidant activity.     

The Early Protective Effect of Glutamine Pretreatment and Ischemia Preconditioning in Renal Ischemia–Reperfusion Injury of Rat

Background

Heat shock proteins (HSP) play an important role in protecting cells against stress.

Methods

Using a rat model, we tested the hypothesis that pretreatment with glutamine (Gln) and ischemia preconditioning (IPC) increase the expression of HSP resulting in attenuation of renal ischemia/reperfusion (I/R) injury. Sprague-Dawley rats were randomized into 4 groups [group I, Gln injection (+), IPC (+); group II, Gln injection (+), IPC (−); group III, saline injection (+), IPC (+); group IV, saline injection (+), IPC (−)]. Renal HSP70 expression was determined by Western blotting and kidney function was assessed by blood urea nitrogen and serum creatinine. Renal cross-sections were microscopically examined for tubular necrosis, exfoliation of tubular epithelial cells, cast formation, and monocyte infiltration.

Results

Gln pretreatment increased intrarenal HSP expression (P = .031). In group I, tubulointerstitial abnormalities were clearly slighter compared with the other groups (P < .001).

Conclusion

Our experiments suggest that (1) a single dose of Gln could induce HSP expression and (2) IPC could relieve renal I/R injury. In addition, IPC combined with Gln pretreatment had a synergic protective effect against renal I/R injury.     

Apigenin Reduces NF-κB and Subsequent Cytokine Production as Protective Effect in a Rodent Animal Model of Lung Ischemia-Reperfusion Injury

Purpose: Lung ischemia–reperfusion injury (LIRI) can complicate lung transplantation or cardiac surgery with cardiopulmonary bypass, increasing morbidity and mortality. In LIRI, pro-inflammatory cytokines are activated, reactive oxygen species are generated and nuclear factor-κB (NF-κB) is up-regulated, altering lung mechanics. We tested the effect of the flavonoid apigenin on a rodent model of LIRI. Methods: Thirty-seven Wistar rats were subjected to LIRI with or without a single or double dose of apigenin. Induction of LIRI involved sternotomy and clamping of either the left lung hilum or the pulmonary artery alone for 30 min, followed by 60 min of reperfusion. Control groups consisted of LIRI plus NaCl, a sham group and a baseline group. At the end of the experiments, both lungs were analyzed by RT-PCR, Western blot, and light microscopy. Results: In placebos, the expression levels of pro-inflammatory markers were increased in both lungs significantly, whereas NF-κB was markedly up-regulated. Administration of apigenin reduced the activation of NF-κB and the expression of TNFα, iNOS, and IL-6. These effects were observed in total lung ischemia. Histology showed greater hemorrhage and exudation in the pulmonary periphery of all groups, whereby damage was practically absent in the central lung regions of the apigenin animals. A second dose of apigenin did not outclass a single one. Conclusions: We conclude that apigenin given intraperitoneally can reduce activation of NF-κB and also attenuate the expression of TNFα, IL-6, and iNOS in a surgical model of LIRI. The surgical procedure itself can induce significant damage to the lungs.     

Retinol and α-Tocopherol in Morbid Obesity and Nonalcoholic Fatty Liver Disease

Background  

We aimed to study serum retinol and α-tocopherol in a cohort of obese patients and their possible association with several obesity-related conditions, given that the former may be implicated in a diminished capacity of anti-inflammatory and antioxidant potential in obese patients.     

Comparative Study on the Inhibitory Effects of α-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage

Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone’s attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl₄)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl₄ after inhaling approximately 1000 or 2000 Bq/m³ radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m³ has the inhibitory effects similar to α-tocopherol treatment at a dose of 300–500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl₄ alone. These findings suggest that radon inhalation has an antioxidative effect against CCl₄-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions.     

The Effect of Diosmin Hesperidin on Intestinal Ischaemia — Reperfusion Injury

Aim: The effect of Diosmin Hesperidin on intestinal ischaemia reperfusion injury was evaluated in an experimental model in rats.

Material and methods: Forty Spraque-Dawley rats were divided into 4 groups of (n = 10) (sham, sham + Diosmin Hesperidin, Reperfusion, Reperfusion + Diosmin Hesperidin). Diosmin Hesperidin oral gavage was administrated at a dose of 50 mg/kg to rats 14 and 2 hours before the operation and 30 minutes of ischaemia and 30 minutes of reperfusion was performed in the groups when appropriate. Ileum samples were resected for histopathological evaluation and tissue malondialdehyde (MDA) and myeloperoxidase (MPA) level determination.

Results: Mean mucosal injury score of IR group (4,50 ± 0,23) was significantly higher than the other groups (p < 0.05). Although mean mucosal injury score of IR + DH group was higher than sham and sham + DH groups, difference was not statistically significant (p > 0.05). Tissue MDA and MPO activities of IR group were 45,55 ± 2.61 nmol/g/wet tissue and 1.68 ± 0.25 U/g/wet tissue respectively and were significantly higher than the other groups (p < 0.008). Although tissue MDA and MPO activities of IR + DH group was higher than sham and sham + DH groups, differences were not statistically significant (p > 0.008).

Conclusion: Diosmin Hesperidin seems to be effective in the prevention of intestinal reperfusion injury.     

The Effect of <Emphasis Type="SmallCaps">l</Emphasis>-arginine and Aprotinin on Intestinal Ischemia–reperfusion Injury

Background Intestinal ischemia/reperfusion (I/R) results in local mucosal injury, systemic injuries, and organ dysfunction. These injuries are characterized by altered microvascular and epithelial permeability and villous damage. Activation of neutrophils, platelets, and endothelial factors are known to be involved in this process. Cytokines such as TNF-α, IL-1, IL-6, and oxygen-derived free radicals are believed to be important pathogenic mediators. Capillary no-reflow is also known to play a role in I/R. The aim of our study was to examine the role of l-arginine, a known nitric oxide (NO) donor, and aprotinin, a protease inhibitor with multiple effects, on intestinal I/R. Methods Pigs weighing 20–25 kg were used. Ischemia was established by clamping the superior mesenteric artery (SMA) at its origin and was sustained for 2 hours. Duration of reperfusion was 2 hours. The animals were divided into four groups: group A, the control group, which was submitted to I/R injury only; group B, in which l-arginine was administered at a rate of 5 mg/kg/min during ischemia and continuing throughout reperfusion; group C, in which aprotinin was administered with an initial bolus dose of 20,000 U/kg during ischemia followed by a continuous dose at 50 U/hour throughout reperfusion; and group D in which both substances were administered. In all groups TNF-α, IL-1, and IL-6 levels were measured using ELISA at baseline, 2 hours of ischemia, and 1 hour and 2 hours of reperfusion. SMA blood flow was measured with a Doppler probe at baseline, 10 min, 1 hour, and 2 hours of reperfusion. Histological changes of the intestinal mucosa were examined and graded on a five-point scale in all groups. Results In the control group, levels of TNF-α, IL-1, and IL-6 were significantly increased during reperfusion (p < 0.05) compared to baseline. Administration of l-arginine and aprotinin led to suppression of the release of TNF-α, IL-1, and IL-6 during reperfusion in a statistically significant manner (all p < 0.05). A synergistic or additive effect of l-arginine and aprotinin was not observed. SMA blood flow in the control group was decreased (p > 0.05) during reperfusion compared to baseline. In animals treated with l-arginine and aprotinin, SMA blood flow during reperfusion was significantly increased (p < 0.05) compared to the control group. Histologic examination of the intestinal mucosa was characterized by flattening of the villi and necrosis in the control group. In the treated animals, less severe histological changes were noted. Conclusions Administration of l-arginine and aprotinin may lead to amelioration of intestinal I/R injury. We did not note a synergistic or additive effect of these two substances. These findings warrant further studies in clinical settings for future treatment efforts. This paper was presented as a poster at the 47th Annual Meeting of the Society for Surgery of the Alimentary Tract, Los Angeles, California, May 20–24, 2006.     

Does Two Episodes of Acute Urinary Retention Lead to Additional Ischemia-Reperfusion Injury in Rat Bladder?

Aim: To determine whether two episodes of acute urinary retention lead to additional ischemia-reperfusion injury due to decompression of the bladder, or not. Materials and methods: Sham, retention and recurrent retention groups consisting of 5, 8 and 8 Wistar Albino male rats were randomized, respectively. After the bladders of rats were emptied with 3F catheter, penile urethras were clamped with aneurism clamp and waited for 30 min after diuresis was forced. At the end of this period, penile clamps were removed and the bladder was again decompressed with 3F catheter and after 30 min removed for examination. In the recurrent retention group, the same process was repeated after an interval of one week. Malonedialdehyde (MDA) levels, indicator of lipid peroxidation and myeloperoxidase (MPO) levels, indicator of leukocyte activation, were examined biochemically in the tissues of the removed bladders. Results: In the retention and recurrent retention groups, the average increase in bladder MDA and MPO values was higher than the values of sham group (P < 0.05), however, no significant difference was determined between retention and recurrent retention groups (P > 0.05). Conclusion: In the bladder tissue, due to acute urinary retention and following decompression process, ischemia-reperfusion injury occurs. Two episodes of acute urinary retention do not lead to additional the ischemia-reperfusion injury that develops in the bladder.     

In vivo Evaluation of the Chitosan-Based Haemostatic Agent Omni-stat® in Porcine Liver Resection and in Liver Injury

Background: Omni-stat?, a polysaccharide made by de-acetylation of chitin, is currently in use as a battlefield topical haemostat. This experimental study undertakes the first evaluation of Omni-stat in an in vivo porcine hepatectomy and liver trauma model. Methods: A model of sequential liver resection was employed: following liver resection, further resections were undertaken in the same animal provided that there was cessation of bleeding from the earlier resection and that haemodynamic stability was maintained. An additional liver trauma injury was undertaken after completion of all resections. Data were collected on heart rate, blood pressure, haematocrit, resection volumes, blood loss and the efficacy of Omni-stat in haemostasis. Results: Eight minor resections and 12 major resections were undertaken. Topical application of Omni-stat to raw post-transection surfaces immediately upon completion of resection achieved complete haemostasis with a single application in 14 of 15 (93%) resections. There was no recurrence of bleeding during the 5-hour protocol. The median time for cessation of bleeding after resection in the Omni-stat group was 3 min (range 3-6). This was not significantly different from time to cessation of bleeding in 5 control resections. There was no difference in blood loss or haemodynamic parameters. Respiratory rate was significantly faster after application of Omni-stat. In 2 liver lacerations, Omni-stat was effective in achieving cessation of haemorrhage. Conclusion: Omni-stat is an effective haemostat in experimental in vivo porcine liver resection and liver trauma. Further evaluation is required to assess its physiological absorption profile in man and its comparative efficacy against commercially established agents.     

Effects of the COX-2 Inhibitor FK3311 on Ischemia—Reperfusion Injury in the Rat Lung

Ischemia–reperfusion injury is induced by activation of the arachidonic acid cascade following the induction of cyclooxygenase-2. This study evaluated the effects of a selective cyclooxygenase-2 inhibitor, FK3311, on warm ischemia–reperfusion injury in the lung. Male Wistar rats were divided into two groups. In the FK3311 group (n = 27), FK3311 (4 mg/kg) was administered intravenously 5 min before ischemia, while in the control group (n = 27) only vehicle was injected. Warm ischemia was induced for 1 h by clamping the left hilus. The arterial oxygen pressure (PaO₂) and saturation (SaO₂) were measured 30 and 120 min after reperfusion. Serum thromboxane B₂ and 6-keto-prostaglandin F_1α were also measured 30 min after reperfusion. Lung specimens were harvested 120 min after reperfusion for histologic examination and polymorphonuclear counts, and immunostained with cyclooxygenase-2. The 1-week survival rate in the two groups was compared. PaO₂ and SaO₂ 30 and 120 min after reperfusion were significantly (p <. 05) better in the FK3311 group. Serum thromboxane B₂ levels were significantly (p <. 05) lower in the FK3311 group. However, there was no significant difference in 6-keto-prostaglandin F_1α. Histologically, tissue damage was mild and polymorphonuclear infiltration was reduced in the FK3311 group compared to the control group. The expression of cyclooxygenase-2 in the alveolar epithelium based on immunostaining was suppressed in the FK3311 group. The 1-week survival rate was significantly (p <. 05) higher in the FK3311 group. We conclude that FK3311 has protective effects on pulmonary ischemia–reperfusion injury, and results in improvement in the 1-week survival rate.     

Effect of Nephrotoxins on Tubulointerstitial Injury and NF-κB Activation in Adriamycin Nephropathy

In a previous study we found that an episode of acute subclinical nephrotoxicity with gentamicin (G) (but not that induced by another proximal tubular cell nephrotoxin: ferric nitrilotriacetate, FeNTA), paradoxically reduced the progression of renal function and injury in uninephrectomized rats with nephrotic glomerular disease due to Adriamycin nephropathy (AN). Here, we hypothesized that subclinical exposure to G reduces early renal cortical tubulointerstitial inflammation and NF-κB activation in AN. To test this hypothesis, male Wistar rats with established AN received either G (10, 40, or 80 mg/kg by daily s.c.i. for 3 days), FeNTA (1.25, 5, or 10 mg/kg by a single i.p.i.), or vehicle (n = 8 per group), 13 to 15 days after disease induction. Although G and FeNTA caused acute tubular necrosis in a dose-dependant manner (day 17), only the highest doses (10 mg/kg and 80 mg/kg) produced an acute elevation in the serum creatinine. On day 33, chronic tubulointerstitial inflammation (tubular atrophy, interstitial ED-1 + /CD8 + cell accumulation) and NF-κB activation were exacerbated only in the groups that caused functional nephrotoxicity. These data suggest that: 1) the protective effect of subclinical G nephrotoxicity in chronic AN does not involve early changes in interstitial inflammation or NF-κB activation; and 2) a single episode of G exposure must be accompanied by clinically apparent nephrotoxicity in order to accelerate progression in a nonuremic model of chronic glomerular disease.     

Effects of Transfusion of Stored Red Blood Cells on Renal Ischemia-Reperfusion–Induced Hepatic Injury in Rats

BackgroundRenal ischemia-reperfusion (IR) injures the liver as well as the kidneys. Transfusion of stored red blood cells (RBCs) triggers inflammatory responses, oxidative stress, and activation of innate immunity. In the present study, we investigated the effect of transfusion of stored RBCs on renal IR-induced hepatic injury.MethodsSprague–Dawley rats were randomly divided into 3 groups based on the following treatments: rats subjected to sham operation (sham group), rats subjected to the induction of renal IR only (RIR group), and rats transfused with stored RBCs 1 hour after the start of reperfusion (RIR-TF group). Renal ischemia was induced for 1 hour, and reperfusion was allowed for 24 hours. After reperfusion, blood and liver tissue samples were obtained.ResultsSerum levels of aspartate and alanine aminotransferase were increased in the RIR-TF group compared with those in the RIR and sham groups. The hepatic mRNA expression levels of heme oxygenase-1 and neutrophil gelatinase-associated lipocalin were increased in the RIR-TF group compared with those in the RIR and sham groups. The mRNA expression level of high mobility group box-1 was also increased in the RIR-TF group compared with that in the RIR group.ConclusionThe transfusion of stored RBCs exacerbates renal IR-induced liver damage. Oxidative stress may be responsible for hepatic injury.     

Effect of α-tocopherol,taurine and selenium on the attenuation of ischemia/reperfusion injury of splanchnic organs

Background: Splanchnic artery occlusion shock is caused by increased capillary permeability and cellular injury precipitated by oxygen derived free radicals following ischemia and reperfusion of splanchnic organs. The purpose of this study was to assess the role of several wellknown oxygen-derived free radical scavengers in ameliorating or preventing this syndrome. Study design: Anesthetized rats were subjected to periods of occlusion of the visceral arteries and reperfusion. Tocopherol, taurine, selenium or a ‘cocktail’ of these three agents was injected subcutaneously for 4 consecutive days prior to operation. Mean arterial blood pressure was measured throughout the experimental period. Fluorometry and technetium-99m pyrophosphate counting of the visceral organs were performed as well as a histologic grading system for intestinal viability. Results: Final mean arterial blood pressure associated with the ‘cocktail’ and selenium groups was 79.1 ± 27.4 mmHg and 83.6 ± 17.8 mmHg, respectively. These values were significantly higher than the control group, 40.8 ± 11.4 mmHg (P < 0.05). Similar patterns of the benefit of selenium in contrast with the other groups were obtained with fluorescein perfusion, radioisotopic activity and histologie analysis. Conclusion: Pretreatment with selenium of splanchnic ischemia and reperfusion in the rat improves mean arterial blood pressure and microcirculatory visceral perfusion. Further analysis of the precise protective mechanism of selenium for reperfusion injury will enable visceral organs to withstand the consequences of increased capillary leakage and oxidant injury.