Propofol attenuates intestinal mucosa injury induced by intestinal ischemia-reperfusion in the rat

Propofol improves survival in a murine model of sepsis via inhibiting Rab5a-mediated intracellular trafficking of TLR4

BACKGROUND

Propofol is a widely used anesthetic and sedative, which has been reported to exert an anti-inflammatory effect. TLR4 plays a critical role in coordinating the immuno-inflammatory response during sepsis. Whether propofol can act as an immunomodulator through regulating TLR4 is still unclear. Given its potential as a sepsis therapy, we investigated the mechanisms underlying the immunomodulatory activity of propofol.

METHODS

The effects of propofol on TLR4 and Rab5a (a master regulator involved in intracellular trafficking of immune factors) were investigated in macrophage (from Rab5a-/- and WT mice) following treatment with lipopolysaccharide (LPS) or cecal ligation and puncture (CLP) in vitro and in vivo, and peripheral blood monocyte from sepsis patients and healthy volunteers.

RESULTS

We showed that propofol reduced membrane TLR4 expression on macrophages in vitro and in vivo. Rab5a participated in TLR4 intracellular trafficking and both Rab5a expression and the interaction between Rab5a and TLR4 were inhibited by propofol. We also showed Rab5a upregulation in peripheral blood monocytes of septic patients, accompanied by increased TLR4 expression on the cell surface. Propofol downregulated the expression of Rab5a and TLR4 in these cells.

CONCLUSIONS

We demonstrated that Rab5a regulates intracellular trafficking of TLR4 and that propofol reduces membrane TLR4 expression on macrophages by targeting Rab5a. Our study not only reveals a novel mechanism for the immunomodulatory effect of propofol but also indicates that Rab5a may be a potential therapeutic target against sepsis.

Attenuation of intestinal ischemia-reperfusion-injury by anesthetics: a potentially protective effect of anesthetic management in experimental studies

Intestinal ischemia-reperfusion injury (IRI) is a potentially severe clinical syndrome after major surgical procedures. In addition to causing intestinal mucosa injury, intestinal IRI further damages distant organs, causing the severity of the condition in patients. So far, effective therapy for intestinal IRI is still absent, and the survival rate of the patients is low. Previous experimental studies have shown that some anesthetics can alleviate intestinal IRI and protect organs while exerting their pharmacological effects, indicating that reasonable perioperative anesthesia management may provide potential benefits for patients to avoid intestinal IRI. These meaningful findings drive scholars to investigate the mechanism of anesthetics in treating intestinal IRI in-depth to discuss the possible new clinical uses. In the present mini-review, we will introduce the protective effects of different anesthetics in intestinal IRI to help us enrich our knowledge in this area.

Etomidate Alleviates Ischemia-Anoxia Reperfusion Injury in Intestinal Epithelial Cells by Inhibiting the Activation of traf6-Regulated NF-KB Signaling

Objective: The present study aimed to investigate the role of etomidate in intestinal cell ischemia and hypoxia-reperfusion injury and potential mechanisms. Method: In this study, we establish the intestinal epithelial cells ischemia-reperfusion model in vitro. CCK8 was used to detect cell viability and flow cytometry assay was used to detect apoptosis levels of treated OGD/R model cells. ELISA measured the expression level of oxidative stress factors and inflammatory factors. Furthermore, western blot assay was used to detect the expression the apoptosis-related factors and TNFR-associated factors in treated OGD/R model cells. Result: Etomidate does not affect the activity of intestinal epithelial cells, and can protect intestinal epithelial cells to reduce ischemiareperfusion injury, and the expression of inflammatory factors and oxidative stress in cells with mild intestinal epithelial ischemia-reperfusion injury. Etomidate alleviates apoptosis of intestinal epithelial ischemia-reperfusion injury cells. Etomidate inhibits the activation of traf6-mediated NF-κB signal during ischemia-anoxia reperfusion of intestinal epithelial cells. Conclusion: Taken together, our study demonstrated that etomidate attenuates inflammatory response and apoptosis in intestinal epithelial cells during ischemic hypoxia-reperfusion injury and inhibits activation of NF-κB signaling regulated by TRAF6.

Assessment of Post-Resuscitation Intestinal Injury and Timing of Bacterial Translocation in Swine Anaesthetized With Propofol-Based Total Intravenous Anaesthesia

Introduction and objectives Bacterial translocation (BT) is the passage of viable bacteria or endotoxins from the gastrointestinal lumen to extra-luminal tissues and is usually observed after intestinal ischaemia-reperfusion injury. The aim of this study was to investigate post-resuscitation BT after cardiac arrest and resuscitation in a swine anaesthetized with propofol-based total intravenous anaesthesia. Materials and methods Eighteen female Landrace/Large White piglets were randomly divided into control (CON), cardiac arrest (CA) and cardiac arrest-cardiopulmonary resuscitation (CA-CPR) groups. In the CON group, the animals were only monitored for two hours. In the CA group, the animals were not resuscitated and underwent necropsy immediately after cardiac arrest. In the CA-CPR group, the animals were resuscitated until the return of spontaneous circulation (ROSC) and were monitored for two hours. The animals of the CON and CA-CPR groups underwent necropsy 24 hours later. Bacterial translocation was assessed by blood and tissue cultures and endotoxin measurement in the portal and systemic circulation. Malondialdehyde content calculation and histological analysis of the intestine were performed in order to estimate ischemia and reperfusion (I/R) tissue damage. Results  Malondialdehyde content, an indicator of oxidative stress, was significantly higher in the CA-CPR group compared to the CA in homogenized ileum (p=0.016). Malondialdehyde content in homogenized colon revealed significantly higher levels in the CA-CPR group compared to the CON (p=0.004) and the CA group (p=0.016). We found significantly higher levels of portal endotoxin in the CA-CPR group compared to the CON (p=0.026) and the CA group (p=0.026). The number of positive mesenteric lymph nodes cultures for E. coli was greater in the CA-CPR group, followed by the CA and CON groups, although the difference was not significant (67%, 33%, and 33%, respectively; p=0.407). Conclusions Malondialdehyde content and portal endotoxin levels do not increase during the cardiac arrest interval, but only after CPR and ROSC. Although the number of positive MLNs cultures was greater in the CA-CPR animals, no statistically significant differences were observed between the three groups due to the short monitoring period.

Effects of propofol on ischemia-reperfusion and traumatic brain injury

Oxidative stress exacerbates brain damage following ischemia-reperfusion and traumatic brain injury (TBI). Management of TBI and critically ill patients commonly involves use of propofol, a sedation medication that acts as a general anesthetic with inherent antioxidant properties. Here we review available evidence from animal model systems and clinical studies that propofol protects against ischemia-reperfusion injury. However, evidence of propofol toxicity in humans exists and manifests as a rare complication, "propofol infusion syndrome" (PRIS). Evidence in animal models suggests that brain injury induces expression of the p75 neurotrophin receptor (p75NTR), which is associated with proapoptotic signaling. p75NTR-mediated apoptosis of neurons is further exacerbated by propofol's superinduction of p75NTR and concomitant inhibition of neurotrophin processing. Propofol is toxic to neurons but not astrocytes, a type of glial cell. Evidence suggests that propofol protects astrocytes from oxidative stress and stimulates astroglial-mediated protection of neurons. One may speculate that in brain injury patients under sedation/anesthesia, propofol provides brain tissue protection or aids in recovery by enhancing astrocyte function. Nevertheless, our understanding of neurologic recovery versus long-term neurological sequelae leading to neurodegeneration is poor, and it is also conceivable that propofol plays a partial as yet unrecognized role in long-term impairment of the injured brain.

The role of PI3K/Akt signal pathway in the protective effects of propofol on intestinal and lung injury induced by intestinal ischemia/reperfusion1

Purpose

To investigate the role of PI3k/Akt signal pathway in the protective effects of propofol on intestinal and lung injury induced by intestinal ischemia/reperfusion(I/R).

Methods

Male Sprague-Dawley rats were subjected to 45 min of ischemia by occluding the superior mesenteric artery and to 2h of reperfusion to establish the model of I/R. Twenty four rats were randomly divided into four groups: Sham, intestinal I/R (II/R), propofol (P), wortmannin (W). In groups P, W, propofol was injected intravenously and continuously at the onset of reperfusion via infusion pump. PI3K inhibitor (wortmannin) was administered intravenously in group W 25 min before ischemia. Intestinal tissues and lung tissues were obtained for determination of histologic injury, wet/dry weight ratio, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and myeloperoxidase (MPO) activities. Meanwhile, the expressions of caspase-3 and phosphorylated Akt (p-Akt) in intestines and lungs were detected by western blot.

Results

Propofol treatment alleviated intestinal and lung morphological changes which were observed in II/R group , Moreover, wet/dry weight ratio, the MDA level, MPO activity and expression of caspase-3 were significantly decreased whereas the SOD activity and p-Akt expression were significantly increased. Notably, the protections were significantly reversed by pretreatment of wortmannin.

Conclusion:

PI3K/Akt pathway activation play a critical role in the protective effects of propofol on intestinal and lung injury induced by ischemia/reperfusion.

Protective effect of propofol on ischemia-reperfusion injury detected by HPLC-MS/MS targeted metabolic profiling

Ischemia-reperfusion injury(IRI), described as tissue damage caused by reversible ischemic injury or hypoxia prior to the blood supply restoration, is a common pathological phenomenon. In recent study, a hypoxia-reoxygenation (H/R) in the presence or absence of propofol posthypoxia treatment (P-PostH) cell model was built to simulate the condition of IRI, and researchers found propofol may protect cells by suppressing autophagic cell death. To investigate the mechanism underling the protective effect of propofol. A metabolomic analysis was performed in this study using ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF- MS) to compare the metabolism during the process of H/R in the presence or absence of P-PostH. A total of 22 metabolites were detected varied after propofol posthypoxia treatment. Pathway analysis revealed these metabolites were mainly involved in the purine metabolic pathway, three carboxylic acid metabolic pathways, alanine, aspartate and glutamate metabolism pathway and lipid metabolism pathway. We measured the level of Hypoxanthine to verify the metabolomics work, for pathway analysis, we detect the level of reactive oxygen species with H/R and P-PostH treatment. Our study achieved a global comparison of metabolism profiling of H/R cell model with or without propofol posthypoxic treatment. The result indicated that propofol can attenuate endothelial injury caused by IRI by reducing oxidative damage.

Microbiome and intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion injury is a severe disease associated with a high mortality. The mechanisms that cause ischemia/reperfusion injury are complex and many factors are involved in the injury formation process; however, the only available treatment is surgical intervention. Recent studies demonstrated that the intestinal microbiome plays a key role in intestinal ischemia/reperfusion injury and there are many factors associated with intestinal bacteria during the formation of the intestinal ischemia/reperfusion injury. Among the Toll-like receptors (TLR), TLR2, TLR4, and their adaptor protein, myeloid differentiation primary-response 88 (MyD88), have been reported to be involved in intestinal ischemia/reperfusion injury. Oxidative stress and nitric oxide are also associated with intestinal bacteria during the formation of the intestinal ischemia/reperfusion injury. This review focuses on our current understanding of the impact of the microbiome, including the roles of the TLRs, oxidative stress, and nitric oxide, on intestinal ischemia/reperfusion injury.

Propofol protects against oxidative-stress-induced COS-7 cell apoptosis by inducing autophagy

Background

In oxidative stress, reactive oxygen species (ROS) production contributes to cellular dysfunction and initiates the apoptotic cascade. Autophagy is considered the mechanism that decreases ROS concentration and oxidative damage. Propofol shows antioxidant properties, but the mechanisms underlying the effect of propofol preconditioning (PPC) on oxidative injury remain unclear. Therefore, we investigated whether PPC protects against cell damage from hydrogen peroxide (H₂O₂)-induced oxidative stress and influences cellular autophagy.

Method

COS-7 cells were randomly divided into the following groups: control, cells were incubated in normoxia (5% CO₂, 21% O₂, and 74% N₂) for 24 h without propofol; H₂O₂, cells were exposed to H₂O₂ (400 µM) for 2 h; PPC + H₂O₂, cells pretreated with propofol were exposed to H₂O₂; and 3-methyladenine (3-MA) + PPC + H₂O₂, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to H₂O₂. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide thiazolyl blue (MTT) reduction. Apoptosis was determined using Hoechst 33342 staining and fluorescence microscopy. The relationship between PPC and autophagy was detected using western blot analysis.

Results

Cell viability decreased more significantly in the H₂O₂ group than in the control group, but it was improved by PPC (100 µM). Pretreatment with propofol effectively decreased H₂O₂-induced COS-7 cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol during apoptosis. Western blot analysis showed that the level of autophagy-related proteins was higher in the PPC + H₂O₂ group than that in the H₂O₂ group.

Conclusion

PPC has a protective effect on H₂O₂-induced COS-7 cell apoptosis, which is mediated by autophagy activation.

Local and Remote Postconditioning Decrease Intestinal Injury in a Rabbit Ischemia/Reperfusion Model

Intestinal ischemia/reperfusion (I/R) injury is a significant problem that is associated with high morbidity and mortality in critical settings. This injury may be ameliorated using postconditioning protocol. In our study, we created a rabbit intestinal I/R injury model to analyze the effects of local ischemia postconditioning (LIPo) and remote ischemia postconditioning (RIPo) on intestinal I/R injury. We concluded that LIPo affords protection in intestinal I/R injury in a comparable fashion with RIPo by decreasing oxidative stress, neutrophil activation, and apoptosis.

Sevoflurane Preconditioning Reduces Intestinal Ischemia-Reperfusion Injury: Role of Protein Kinase C and Mitochondrial ATP-Sensitive Potassium Channel

Ischemic preconditioning (IPC) has been considered to be a potential therapy to reduce ischemia-reperfusion injury (IRI) since the 1980s. Our previous study indicated that sevoflurane preconditioning (SPC) also reduced intestinal IRI in rats. However, whether the protective effect of SPC is similar to IPC and the mechanisms of SPC are unclear. Thus, we compared the efficacy of SPC and IPC against intestinal IRI and the role of protein kinase C (PKC) and mitochondrial ATP-sensitive potassium channel (mK_ATP) in SPC. A rat model of intestinal IRI was used in this study. The superior mesenteric artery (SMA) was clamped for 60 min followed by 120 min of reperfusion. Rats with IPC underwent three cycles of SMA occlusion for 5 min and reperfusion for 5 min before intestinal ischemia. Rats with SPC inhaled sevoflurane at 0.5 minimum alveolar concentration (MAC) for 30 min before the intestinal ischemic insult. Additionally, the PKC inhibitor Chelerythrine (CHE) or mK_ATP inhibitor 5-Hydroxydecanoic (5-HD) was injected intraperitoneally before sevoflurane inhalation. Both SPC and IPC ameliorated intestinal IRI-induced histopathological changes, decreased Chiu’s scores, reduced terminal deoxyribonucleotide transferase-mediated dUTP nick end labeling (TUNEL) positive cells in the epithelium, and inhibited the expression of malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α). These protective effects of SPC were similar to those of IPC. Pretreatment with PKC or mK_ATP inhibitor abolished SPC—induced protective effects by increasing Chiu’s scores, down-regulated the expression of Bcl-2 and activated caspase-3. Our results suggest that pretreatment with 0.5 MAC sevoflurane is as effective as IPC against intestinal IRI. The activation of PKC and mK_ATP may be involved in the protective mechanisms of SPC.

Intravenous Infusion of Dexmedetomidine Combined Isoflurane Inhalation Reduces Oxidative Stress and Potentiates Hypoxia Pulmonary Vasoconstriction during One-Lung Ventilation in Patients

Inhalation anesthetic isoflurane inhibits hypoxia pulmonary vasoconstriction (HPV), while dexmedetomidine (Dex) could reduce the dose of isoflurane inhalation and potentiate HPV, but the mechanism is unclear. Inhibition of reactive oxygen species (ROS) production can favor HPV during one-lung ventilation (OLV). Similarly, nitric oxide (NO), an important endothelium-derived vasodilator in lung circulation, can decrease the regional pulmonary vascular resistance of ventilated lung and reduce intrapulmonary shunting. We hypothesized that Dex may augment HPV and improve oxygenation during OLV through inhibiting oxidative stress and increasing NO release. Patients undergoing OLV during elective thoracic surgery were randomly allocated to either isoflurane + saline (NISO, n = 24) or isoflurane + dexmedetomidine (DISO, n = 25) group. Anesthesia was maintained with intravenous remifentanil and inhalational isoflurane (1.0–2.0%), with concomitant infusion of dexmedetomidine 0.7 μgkg⁻¹h⁻¹ in DISO and saline 0.25 mL kg⁻¹h⁻¹ in NISO group. Hemodynamic variables or depth of anesthesia did not significantly differ between groups. Administration of Dex significantly reduced Qs/Qt and increased PaO₂ after OLV, accompanied with reduced lipid peroxidation product malondialdehyde and higher levels of SOD activity as well as serum NO (all P < 0.05 DISO versus NISO). In conclusion, reducing oxidative stress and increasing NO release during OLV may represent a mechanism whereby Dex potentiates HPV.

Propofol Attenuates Small Intestinal Ischemia Reperfusion Injury through Inhibiting NADPH Oxidase Mediated Mast Cell Activation

Both oxidative stress and mast cell (MC) degranulation participate in the process of small intestinal ischemia reperfusion (IIR) injury, and oxidative stress induces MC degranulation. Propofol, an anesthetic with antioxidant property, can attenuate IIR injury. We postulated that propofol can protect against IIR injury by inhibiting oxidative stress subsequent from NADPH oxidase mediated MC activation. Cultured RBL-2H3 cells were pretreated with antioxidant N-acetylcysteine (NAC) or propofol and subjected to hydrogen peroxide (H2O2) stimulation without or with MC degranulator compound 48/80 (CP). H2O2 significantly increased cells degranulation, which was abolished by NAC or propofol. MC degranulation by CP further aggravated H2O2 induced cell degranulation of small intestinal epithelial cell, IEC-6 cells, stimulated by tryptase. Rats subjected to IIR showed significant increases in cellular injury and elevations of NADPH oxidase subunits p47(phox) and gp91(phox) protein expression, increases of the specific lipid peroxidation product 15-F2t-Isoprostane and interleukin-6, and reductions in superoxide dismutase activity with concomitant enhancements in tryptase and β-hexosaminidase. MC degranulation by CP further aggravated IIR injury. And all these changes were attenuated by NAC or propofol pretreatment, which also abrogated CP-mediated exacerbation of IIR injury. It is concluded that pretreatment of propofol confers protection against IIR injury by suppressing NADPH oxidase mediated MC activation.

Treatment with Recombinant Trichinella spiralis Cathepsin B-like Protein Ameliorates Intestinal Ischemia/Reperfusion Injury in Mice by Promoting a Switch from M1 to M2 Macrophages

Intestinal ischemia/reperfusion (I/R) injury, in which macrophages play a key role, can cause high morbidity and mortality. The switch from classically (M1) to alternatively (M2) activated macrophages, which is dependent on the activation of STAT6 signaling, has been shown to protect organs from I/R injuries. In the current study, the effects of recombinant Trichinella spiralis cathepsin B-like protein (rTsCPB) on intestinal I/R injury and the potential mechanism related to macrophage phenotypes switch were investigated. In a mouse I/R model undergoing 60-min intestinal ischemia followed by 2-h or 7-d reperfusion, we demonstrated that intestinal I/R caused significant intestinal injury and induced a switch from M2 to M1 macrophages, evidenced by a decrease in levels of M2 markers (arginase-1 and found in inflammatory zone protein), an increase in levels of M1 markers (inducible NO synthase and CCR7), and a decrease in the ratio of M2/M1 macrophages. RTsCPB reversed intestinal I/R-induced M2-M1 transition and promoted M1-M2 phenotype switch evidenced by a significant decrease in M1 markers, an increase in M2 markers, and the ratio of M2/M1 macrophages. Meanwhile, rTsCPB significantly ameliorated intestinal injury and improved intestinal function and survival rate of animals, accompanied by a decrease in neutrophil infiltration and an increase in cell proliferation in the intestine. However, a selective STAT6 inhibitor, AS1517499, reversed the protective effects of rTsCPB by inhibiting M1 to M2 transition. These findings suggest that intestinal I/R injury causes a switch from M2 to M1 macrophages and that rTsCPB ameliorates intestinal injury by promoting STAT6-dependent M1 to M2 transition.

Propofol attenuated acute kidney injury after orthotopic liver transplantation via inhibiting gap junction composed of connexin 32

BACKGROUND

Postliver transplantation acute kidney injury (AKI) severely affects patient survival, whereas the mechanism is unclear and effective therapy is lacking. The authors postulated that reperfusion induced enhancement of connexin32 (Cx32) gap junction plays a critical role in mediating postliver transplantation AKI and that pretreatment/precondition with the anesthetic propofol, known to inhibit gap junction, can confer effective protection.

METHODS

Male Sprague-Dawley rats underwent autologous orthotopic liver transplantation (AOLT) in the absence or presence of treatments with the selective Cx32 inhibitor, 2-aminoethoxydiphenyl borate or propofol (50 mg/kg) (n = 8 per group). Also, kidney tubular epithelial (NRK-52E) cells were subjected to hypoxia-reoxygenation and the function of Cx32 was manipulated by three distinct mechanisms: cell culture in different density; pretreatment with Cx32 inhibitors or enhancer; Cx32 gene knock-down (n = 4 to 5).

RESULTS

AOLT resulted in significant increases of renal Cx32 protein expression and gap junction, which were coincident with increases in oxidative stress and impairment in renal function and tissue injury as compared to sham group. Similarly, hypoxia-reoxygenation resulted in significant cellular injury manifested as reduced cell growth and increased lactate dehydrogenase release, which was significantly attenuated by Cx32 gene knock-down but exacerbated by Cx32 enhancement. Propofol inhibited Cx32 function and attenuated post-AOLT AKI. In NRK-52E cells, propofol reduced posthypoxic reactive oxygen species production and attenuated cellular injury, and the cellular protective effects of propofol were reinforced by Cx32 inhibition but cancelled by Cx32 enhancement.

CONCLUSION

Cx32 plays a critical role in AOLT-induced AKI and that inhibition of Cx32 function may represent a new and major mechanism whereby propofol reduces oxidative stress and subsequently attenuates post-AOLT AKI.

Propofol prevents lung injury after intestinal ischemia-reperfusion by inhibiting the interaction between mast cell activation and oxidative stress

AIMS

Both mast cells and oxidative stress are involved in acute lung injury (ALI) induced by intestinal ischemia-reperfusion (IIR). The aim of this study was to investigate whether propofol could improve IIR-induced ALI through inhibiting their interaction.

MAIN METHODS

Repetitive, brief IIR or IIR+compound 48/80 was performed in adult Sprague-Dawley rats pretreated with saline, apocynin or propofol. And their lungs were excised for histology, ELISA and protein-expression measurements 2h after reperfusion.

KEY FINDINGS

Rats pretreated with saline developed critical ALI 2h after IIR. We found significant elevations in lung injury scores, lung wet/dry ratio and gp91phox, p47phox, intercellular cell adhesion molecule-1 protein expressions and higher level of malondialdehyde, interleukin-6 contents, and myeloperoxidase activities, as well as significant reductions in superoxide dismutase activities, accompanied with increases in mast cell degranulation evidenced by significant increases in mast cell counts, β-hexosaminidase concentrations, and tryptase expression. And the lung injury was aggravated in the presence of compound 48/80. However, pretreated with propofol and apocynin not only ameliorated the IIR-mediated pulmonary changes beyond the biochemical changes but also reversed the changes that were aggravated by compound 48/80.

SIGNIFICANCE

Propofol protects against IIR-mediated ALI, most likely by inhibiting the interaction between oxidative stress and mast cell degranulation.

Propofol activation of the Nrf2 pathway is associated with amelioration of acute lung injury in a rat liver transplantation model

Objective. This study aimed to investigate whether propofol pretreatment can protect against liver transplantation-induced acute lung injury (ALI) and to explore whether Nrf2 pathway is involved in the protections provided by propofol pretreatment. Method. Adult male Sprague-Dawley rats were divided into five groups based on the random number table. Lung pathology was observed by optical microscopy. Lung water content was assessed by wet/dry ratio, and PaO₂ was detected by blood gas analysis. The contents of H₂O₂, MDA, and SOD activity were determined by ELISA method, and the expression of HO-1, NQO1, Keap1, and nuclear Nrf2 was assayed by western blotting. Results. Compared with saline-treated model group, both propofol and N-acetylcysteine pretreatment can reduce the acute lung injury caused by orthotopic autologous liver transplantation (OALT), decrease the lung injury scores, lung water content, and H₂O₂ and MDA levels, and improve the arterial PaO₂ and SOD activity. Furthermore, propofol (but not N-acetylcysteine) pretreatment especially in high dose inhibited the expression of Keap1 and induced translocation of Nrf2 into the nucleus to further upregulate the expression of HO-1 and NQO1 downstream. Conclusion. Pretreatment with propofol is associated with attenuation of OALT-induced ALI, and the Nrf2 pathway is involved in the antioxidative processes.

Effect of dexmedetomidine pretreatment on lung injury following intestinal ischemia-reperfusion

Reperfusion injury is tissue damage caused by the re-supply of blood following a period of ischemia in tissues. Intestinal ischemia-reperfusion injury (IRI) is an extremely common clinical event associated with distant organ injury. The intestine serves as the initial organ of multi-system organ dysfunction syndrome. It is extremely important to identify a method to protect against IRI, as it is a key factor associated with morbidity and mortality in patients. In the present study, the protective effects of pretreatment with dexmedetomidine hydrochloride were investigated. Rats were divided into six groups and models of intestinal ischemia were created in the five groups. Certain groups were pretreated with dexmedetomidine hydrochloride. The levels of TNF-α and IL-6 were measured by enzyme-linked immunosorbent assay in order to evaluate the injury. Tissue sections were stained with hematoxylin and eosin to visualize the damage. qPCR and western blotting were performed to examine the inflammatory status. Pretreatment with various doses of dexmedetomidine hydrochloride significantly reduced the pathological scores and the inflammatory reaction. The levels of TNF-α, IL-6, TLR4 and MyD88 were decreased in the dexmedetomidine hydrochloride treatment groups compared with those in the sham control and untreated ischemia reperfusion groups. The results of the present study indicate that pretreatment with dexmedetomidine hydrochloride may be a useful method of reducing the damage caused by IRI.

Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6) was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS). In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries.

Ischemic postconditioning during reperfusion attenuates intestinal injury and mucosal cell apoptosis by inhibiting JAK/STAT signaling activation

The present study attempts to evaluate the role of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling in intestinal ischemia/reperfusion (I/R)-induced intestinal injury and whether immediate ischemic postconditioning ameliorates intestinal injury via attenuation of intestinal mucosal apoptosis subsequent to inhibiting JAK/STAT signaling activation. Anesthetized adult male Sprague-Dawley rats were subjected to superior mesenteric artery occlusion consisting of 60 min of ischemia and 2 h of reperfusion; sham laparotomy served as controls. Animals received either subcutaneous administration of JAK2 inhibitor (AG490, 8 mg/kg) or STAT inhibitor (rapamycin, 0.4 mg/kg) 30 min before ischemia. Ischemic postconditioning was performed by three cycles of 30-s reperfusion and 30-s ischemia initiated immediately upon reperfusion. It was found that intestinal I/R resulted in conspicuous intestinal injury evidenced by significant increases in Chiu's score, lactic acid, and diamine oxidase activity, accompanied with increases in plasma levels of 15-F2t-isoprostane, endothelin 1, and thromboxane B2, as well as increase in the intestinal tissue myeloperoxidase activity. Meanwhile, the apoptotic index and cleaved caspase 3, phosphorylated JAK2, phosphorylated STAT1, and phosphorylated STAT3 expression were significantly enhanced versus sham control. Both ischemic postconditioning and pretreatment with AG490 or rapamycin significantly attenuated all the above changes. These results indicate that JAK/STAT pathway activation plays a critical role in I/R-induced intestinal injury, which is associated with increased oxidative stress, neutrophil accumulation, intestinal mucosal apoptosis, and microcirculation disturbance. Ischemic postconditioning mediates attenuation of intestinal I/R injury, and cell apoptosis may be attributable to the JAK/STAT signaling inhibition.

A comparison of the effects of epidural and spinal anesthesia with ischemia-reperfusion injury on the rat transverse rectus abdominis musculocutaneous flap

The purpose of this study is to compare the effects of spinal and epidural anesthesia on a rat transverse rectus abdominus myocutaneous flap ischemia-reperfusion injury model.Forty Sprague-Dawley rats were divided into 4 experimental groups: group I (n = 10), sham group; group II (n = 10), control group; group III (n = 10), epidural group; and group IV (n = 10), spinal group. After the elevation of the transverse rectus abdominus myocutaneous flaps, all groups except for the sham group were subjected to normothermic no-flow ischemia for 4 hours, followed by a reperfusion period of 2 hours. At the end of the reperfusion period, biochemical and histopathological evaluations were performed on tissue samples.Although there was no significant difference concerning the malonyldialdehyde, nitric oxide, and paraoxonase levels in the spinal and epidural groups, the total antioxidant state levels were significantly increased, and the total oxidative stress levels were significantly decreased in the epidural group in comparison to the spinal group. The pathological evaluation showed that findings related to inflammation, nuclear change rates and hyalinization were significantly higher in the spinal group compared with the epidural group.Epidural anesthesia can be considered as a more suitable method that enables a decrease in ischemia-reperfusion injuries in the muscle flaps.

Treatment with Astragalus membranaceus produces antioxidative effects and attenuates intestinal mucosa injury induced by intestinal ischemia-reperfusion in rats

Astragalus membranaceus, also known as huang qi, a traditional Chinese medicine, is often used in formulas for deficiency of vital energy characterized by limb weakness, pale face, and dizziness. Previous studies have shown that Astragalus membranaceus could attenuate intestinal ischemia-reperfusion injury induced by hemorrhagic shock in rats; however, the underlying mechanism still remains unclear. Using a hemorrhagic shock rat model to examine the effect of Astragalus membranaceus on intestinal mucosa injury induced by ischemia-reperfusion, we found that treatment (20 g crude drugs/kg, i.v.) produced antioxidative effects in the intestinal mucosa of rats after ischemia-reperfusion (p < 0.05). We also found that Astragalus membranaceus could partly attenuate intestinal mucosa ischemia-reperfusion injury (chiu's score, apoptosis index p < 0.05). These results suggest that Astragalus membranaceus reduces intestinal mucosa injury induced by ischemia-reperfusion in rats, at least in part, through its anti-oxidative effects.

Antioxidant effects of propofol on tourniquet-induced ischemia-reperfusion injury: an experimental study

PURPOSE

This experimental study aimed to investigate the antioxidant effects of propofol anesthesia at induction doses in a rat skeletal muscle ischemia/reperfusion injury model.

METHODS

Twenty-six rats were randomly divided into three groups to receive one of the following interventions: sham operation (n = 6), ischemia/reperfusion (I/R) injury (n = 10), or propofol administration in addition to I/R injury (n = 10). I/R injury was attained by 2-h clamping of femoral artery followed by 3-h perfusion. Then blood and tissue samples were collected for biochemical analysis and histopathologic examination. Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) enzyme activities and nitric oxide (NO) and malondialdehyde (MDA) levels were measured in both plasma and muscle tissue. In addition, catalase (CAT) activity and protein carbonyl (PC) content were measured in muscle tissue.

RESULTS

I/R group had significantly higher SOD activity (9.05 versus 5.63 and 6.18 U/mL, P < 0.05) and NO level (46.77 versus 30.62 and 33.90 μmol/L, P < 0.05) compared with sham-operated group and I/R plus propofol group. In addition, GSH-Px activity of the I/R group was significantly higher than sham-operated group (1.26 versus 1.05 U/mL, P < 0.05). I/R group had significantly higher tissue activities of CAT (0.11 versus 0.06 and 0.04 k/g protein, P < 0.05) and SOD (0.12 versus 0.08 and 0.07 U/mg protein, P < 0.05) compared with the sham and I/R plus propofol group. Histopathologic examination showed that I/R plus propofol group had significantly lower degeneration (P = 0.021) and inflammation (P = 0.028) scores compared with I/R group.

CONCLUSION

Propofol anesthesia seems to enhance the antioxidant capacity against tourniquet induced ischemia-reperfusion injury.

Proteomic analysis of intestinal ischemia/reperfusion injury and ischemic preconditioning in rats reveals the protective role of aldose reductase

Intestinal ischemia/reperfusion (I/R) injury is a critical condition associated with high morbidity and mortality. Studies show that ischemic preconditioning (IPC) can protect the intestine from I/R injury. However, the underlying molecular mechanisms of this event have not been fully elucidated. In the present study, 2-DE combined with MALDI-MS was employed to analyze intestinal mucosa proteomes of rat subjected to I/R injury in the absence or presence of IPC pretreatment. The protein content of 16 proteins in the intestinal mucosa changed more than 1.5-fold following intestinal I/R. These proteins were, respectively, involved in the cellular processes of energy metabolism, anti-oxidation and anti-apoptosis. One of these proteins, aldose reductase (AR), removes reactive oxygen species. In support of the 2-DE results, the mRNA and protein expressions of AR were significantly downregulated upon I/R injury and enhanced by IPC as confirmed by RT-PCR and western blot analysis. Further study showed that AR-selective inhibitor epalrestat totally turned over the protective effect of IPC, indicating that IPC confers protection against intestinal I/R injury primarily by increasing intestinal AR expression. The finding that AR may play a key in intestinal ischemic protection might offer evidences to foster the development of new therapies against intestinal I/R injury.

Hydrogen sulfide protects from intestinal ischaemia–reperfusion injury in rats

Objectives

Hydrogen sulfide (H2S) is an endogenously gaseous mediator, regulating many pathophysiological functions in mammalian cells. H2S has been shown to inhibit myocardial ischaemia–reperfusion (I/R) injury. However, little is known about whether H2S could modulate intestinal I/R injury. This study aimed to investigate the effect of H2S on intestinal I/R injury and potential mechanism(s) underlying the action of H2S in regulating the development of intestinal I/R injury in rats.

Methods

Following surgical induction of intestinal I/R injury for 1 h, groups of Sprague-Dawley rats were treated with, or without, tetramethylpyrazine (8 mg/kg), or sodium hydrosulfide (NaHS, an H2S donor at 7 or 14 μmol/kg) 30 min after occlusion. All rats were sacrificed immediately after the reperfusion. Their intestinal injury, together with that of sham-control rats, was histologically examined and their sera and intestinal malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (GSH-Px) activities were characterized by biochemical analysis.

Key findings

The results showed that NaHS significantly reduced intestinal I/R injury and the levels of sera and intestinal MDA activity, and dramatically increased the levels of serum and intestinal SOD and GSH-Px activity.

Conclusions

The results suggest that H2S protects from intestinal I/R injury in rats, which is associated with increase in the activity of antioxidant enzymes.

The role of KATP channels on propofol preconditioning in a cellular model of renal ischemia-reperfusion

BACKGROUND

Propofol (2,6-diisopropylphenol) has been shown to protect several organs, including the kidneys, from ischemia-reperfusion (I-R)-induced injury. Although propofol affects adenosine triphosphate-sensitive potassium (K(ATP)) channels in nonrenal tissues, it is still not clear by which mechanisms propofol protects renal cells from such damage. In this study, we investigated whether propofol induces renal preconditioning through renal K(ATP) channels.

METHODS

A reversible ATP depletion (antimycin A) followed by restoration of substrate supply in LLC-PK1 cells was used as an in vitro model of renal I-R. Cell viability was assessed by dimethylthiazol-diphenyltetrazol bromide and trypan blue dye exclusion test assays. Apoptosis was evaluated by annexin V-fluorescein isothiocyanate staining by flow cytometry and immunofluorescence. Propofol treatments were initiated at various time intervals: 1 or 24 h before ischemia, only during ischemia, or only during reperfusion. To evaluate the mechanisms of propofol protection, specific K(ATP) channel inhibitors or activators were used in some experiments during propofol pretreatment.

RESULTS

Propofol attenuated I-R injury on LLC-PK1 cells when present either 1 or 24 h before initiated I-R, and also during the recovery period, but not when added only during ischemia. Propofol pretreatment significantly protected LLC-PK1 from I-R-induced apoptosis. The protective effect of propofol was prevented by glibenclamide (a sarcolemmal ATP-dependent K(+) channel blocker) and decreased by 5-hydroxidecanoic acid (a mitochondrial ATP-dependent K(+) channel blocker), but it was not modified by diazoxide (a selective opener of ATP-sensitive K(+) channel).

CONCLUSION

Propofol protected cells against apoptosis induced by I-R. This protection was probably due to a preconditioning effect of propofol and was, at least in part, mediated by K(ATP) channels.

Proteomics of ischemia/reperfusion injury in rat intestine with and without ischemic postconditioning

BACKGROUND

Intestinal ischemia/reperfusion (I/R) injury is a critical condition associated with high morbidity and mortality. Our previous study showed that ischemic postconditioning (IPo) protects the intestinal mucosa from I/R injury. However, the precise molecular mechanisms of this event remain poorly elucidated. The aim of this study was to investigate the differentially expressed proteins of intestinal mucosa after intestinal I/R with or without IPo, and to explore the potential mechanisms of intestinal I/R injury and the protective effect of IPo in relation to the differential proteins.

MATERIALS AND METHODS

Intestinal I/R injury was established by occluding the superior mesenteric artery (SMA) for 60 min followed by 60 min reperfusion. The rats were randomly allocated into one of three groups based upon the intervention (n = 8); sham : sham surgical preparation including isolation of the SMA without occlusion was performed; injury: there was no intervention either before or after SMA occlusion; IPo: three cycles of 30 s reperfusion-30 s reocclusion were imposed immediately upon reperfusion. A comparative proteomics approach with two-dimensional gel electrophoresis was used to isolate proteins in intestinal mucosa, the expression of which were regulated by I/R injury post-treated with or without IPo. The differentially displayed proteins were identified through matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS).

RESULTS

Image analysis revealed that an average of 1300 protein spots were detected on each gel; 16 and 9 proteins showing more than 1.5-fold difference were identified between the Sham versus Injury group and injury group versus IPo group, respectively. The identified proteins were functionally involved in the cellular processes of energy metabolism, anti-oxidation, and anti-apoptosis.

CONCLUSIONS

This study provided new clues for understanding the mechanisms of IPo against intestinal I/R injury.

Intestinal ischaemia/reperfusion upregulates beta-defensin-2 expression and causes acute lung injury in the rat

OBJECTIVE

Human beta-defensin-2 (BD-2) is a positive ion antimicrobial peptide. We investigated the effects of intestinal ischaemia/reperfusion (II/R) on rat BD-2 mRNA and protein expressions in rat lung to address the potential role of BD-2 in acute lung injury (ALI) induced by II/R.

METHODS

Rats were randomly divided into two groups (n=36 each). (i) Sham control and (ii) II/R group (1h superior mesenteric artery clamping, followed by reperfusion of different durations). In II/R group, 6 animals were sacrificed at 0min, 15min, 30min, 60min, 3h and 6h after reperfusion, and serum, lung tissue and bronchoalveolar lavage fluid were harvested. Samples were taken at the corresponding time points in the sham group. Lung histological changes were observed under microscope and the pulmonary permeability index (PPI) was calculated. The lung tissue levels of TNFalpha were detected by ELISA. BD-2 mRNA and protein expressions were examined by RT-PCR and western blotting techniques, respectively.

RESULTS

ALI induced by II/R was confirmed by pathological examination and significantly increased PPI (P<0.05 or 0.01). II/R significantly increased the lung TNFalpha levels and upregulated the expressions of BD-2 mRNA and protein expressions (P<0.05 or 0.01). BD-2 mRNA expression was significantly positively correlated to the lung TNFalpha level (r=0.823, P<0.01) and negatively correlated to PPI (r=-0.615, P<0.05).

CONCLUSION

II/R can upregulate BD-2 mRNA and protein expressions in rat lung. BD-2 could be an innate protective factor against II/R-induced lung injury.

Immediate postconditioning during reperfusion attenuates intestinal injury

OBJECTIVE

To test the hypothesis that immediate but not delayed ischemic postconditioning (IPo) during reperfusion attenuates intestinal injury, and that ischemic preconditioning (IPC) and IPo may confer synergy in intestinal protection.

DESIGN AND SETTING

Prospective laboratory animal study with concurrent control.

SUBJECTS

Adult Sprague-Dawley rats.

INTERVENTIONS

Intestinal ischemia/reperfusion (II/R) injury in rats was produced by clamping superior mesenteric artery for 60 min followed by 60 min reperfusion; IPC was elicited by 10 min ischemia and 10 min reperfusion before index ischemia; IPo was performed by three cycles of 30 s reperfusion and 30 s ischemia initiated either immediately at the onset of reperfusion (IPo) or after reperfusion for 3 min (delayed-IPo). Combination of IPC and IPo was performed by combining both protocols.

MEASUREMENTS AND MAIN RESULTS

Intestinal ischemia/reperfusion resulted in significant intestinal injury evidenced as significant increase in Chiu's scores and wet-to-dry intestine weight ratio accompanied with increases in plasma levels of tumor necrosis factor-alpha and interleukin-6, as well as increases in the intestinal tissue lipid peroxidation product malonediadehyde and myeloperoxidase activity as compared to control animals (all P < 0.05). All these changes were significantly attenuated either by IPC or IPo or their combination (P < 0.05), and not by delayed-IPo (P > 0.05). IPC and IPo showed synergistic protection compared with either protocol alone.

CONCLUSION

Ischemic postconditioning reduces intestinal injury, in part, by inhibiting oxidative injury, neutrophils filtration and proinflammatory response. The early period of reperfusion is critical to intestinal protection by IPo, and intestinal protection with IPo can be enhanced by IPC.

Propofol pretreatment reduces ceramide production and attenuates intestinal mucosal apoptosis induced by intestinal ischemia/reperfusion in rats

BACKGROUND

Apoptosis has been shown to be a major mode of intestinal epithelial cell death caused by intestinal ischemia/reperfusion (II/R), a condition that is associated with increased oxidative stress. Ceramide has been proposed as a messenger of apoptosis. We investigated if pretreatment with propofol, an anesthetic with antioxidant properties, could reduce ceramide production, and consequently, mucosal epithelial apoptosis induced by II/R in rats.

METHODS

Rat II/R injury was produced by clamping the superior mesenteric artery for 1 h followed by 3 h of reperfusion. Thirty rats were randomly allocated into control, injury (II/R) and propofol (pretreatment) groups (n = 10 per group). In the propofol group, propofol 50 mg/kg, a dose that has been shown to cause the loss of reflex responses to a painful stimulus while remaining sensitive to skin incision in rats, was administered intraperitoneally 30 min before inducing intestinal ischemia, while animals in control and untreated injury groups received an equal volume of intralipid. Intestinal mucosal epithelial apoptosis was detected via electron microscopy and TUNEL analysis. Lipid oxidation product malondialdehyde and the activities of superoxide dismutase were assessed by colorimetric analyses. Ceramide generation and sphingomyelinase mRNA expression in intestinal mucosa were determined by high performance thin layer chromatography and reverse transcriptase polymerase chain reaction, respectively.

RESULTS

II/R caused intestinal mucosal epithelial apoptosis and over-production of ceramide accompanied by up-regulation of sphingomyelinase mRNA expression and increases in lipid oxidation (all P < 0.01 versus control). Propofol pretreatment significantly attenuated these changes (all P < 0.01, propofol versus injury).

CONCLUSION

The findings indicate that propofol pretreatment attenuates II/R-induced intestinal epithelial apoptosis, which might be attributable to its antioxidant property modulating the ceramide pathway.

Immediate but not delayed postconditioning during reperfusion attenuates acute lung injury induced by intestinal ischemia/reperfusion in rats: comparison with ischemic preconditioning

BACKGROUND

A previous study has shown that brief period of repetitive superior mesenteric artery (SMA) occlusion and reperfusion applied at the onset of reperfusion, ischemic postconditioning (IPo), attenuates intestinal injury after intestinal ischemia/reperfusion (II/R). This study tested the hypothesis that IPo would attenuate II/R-induced acute lung injury, which is comparable to ischemic preconditioning (IPC) and the brief period of postconditioning applied at the onset of reperfusion is critical to pulmonary protection by IPo.

METHODS

Rat II/R injury was produced by clamping SMA for 60 min followed by 60 min of reperfusion. The rats were randomly allocated into one of five groups based upon the intervention (n = 8): sham operation (Sham): sham surgical preparation including isolation of the SMA without occlusion was performed; Injury: there was no intervention either before or after SMA occlusion; ischemia preconditioning (IPC): the SMA was occluded for 10 min followed by 10 min of reperfusion before prolonged occlusion; ischemia postconditioning (IPo): three cycles of 30 sec reperfusion-30 sec reocclusion were imposed immediately upon reperfusion (3 min total intervention); delayed postconditioning: clamping was completely released for full reperfusion for 3 min (the duration of the IPo algorithm), after which three cycles of 30 sec occlusion and reperfusion were applied.

RESULTS

Histologic results showed severe damage in rat lungs in the injury group evidenced by increased lung wet/dry weight ratio and pulmonary permeability index, which was accompanied by increases in the levels of plasma TNFalpha and IL-6, the pulmonary malondialdehyde (MDA), and the pulmonary myeloperoxidase (MPO) activity and a decrease in superoxide dismutase (SOD) activity. IPo, not delayed IPo, could significantly attenuate lung injury and improve the above variables, which was comparable to IPC.

CONCLUSIONS

IPo at onset of reperfusion reduces acute lung injury induced by II/R, which may be mediated, in part, by inhibiting oxidant generation, neutrophils filtration, and proinflammatory mediators releases. The early period of reperfusion in the rat model is critical to pulmonary protection by IPo. IPo may improve outcome in clinical conditions associated with II/R.

Propofol and N-Acetylcysteine attenuate oxidative stress induced by intestinal ischemia/reperfusion in rats: Protein carbonyl detection by immunoblotting

PURPOSE: To evaluate the antioxidant effect of Propofol and N-Acetylcysteine (NAC) on intestinal ischemia/reperfusion (I/R) in rats by determining carbonyl protein level. METHODS: Forty Wistar rats were randomly assigned into the following groups: Control; Sham; I/R with Propofol; I/R with Propofol and NAC; I/R with Ketamine and Xylazine. The I/R groups underwent 60 minutes of ischemia and an equal period of reperfusion. Blood samples, collected by cardiac punction, were centrifuged for plasma obtainment. Protein carbonyl level in plasma samples was determined by immunoblotting. RESULTS: No significant difference in protein carbonyl level was found between Control and Sham groups (P>0.05). The highest reduction in protein carbonyl level (P<0.05) was obtained with the administration of Propofol and NAC (Group 4) in intestinal I/R procedure. CONCLUSION: The administration of Propofol and NAC showed the best antioxidant effect on oxidative stress in rats that underwent intestinal I/R procedure, suggesting a synergistic interaction.

Mechanical bowel preparation with different solutions in rats with selective left colonic ischemia and reperfusion injury

BACKGROUND

The aim of this study was to evaluate the effects of preoperative mechanical bowel preparation (MBP) on colonic ischemia/reperfusion (I/R) injury.

METHODS

Seventy adult male Sprague-Dawley rats were divided randomly into 7 equal groups of 10 rats each. Groups were assigned as follows: group I = sham surgery; group II = I/R of left colon (control group); group III = intravenous heparin and metronidazole followed by I/R of the left colon; groups IV through VII = before I/R of the left colon, heparin and metronidazole and MBP were performed with sodium chloride (NaCl), Na phosphate, polyethylene glycol, and mannitol, respectively. Histopathologic and biochemical parameters were evaluated.

RESULTS

According to the histopathologic changes, the groups least affected by I/R injury were groups V and VII. Catalase activity was significantly higher in groups V and VII, and copper-zinc superoxide dismutase activity was significantly higher in group VII compared with the control group (P <.002).

CONCLUSIONS

MBP with sodium phosphate and mannitol appears to be more protective against I/R injury.