Protective Effects of Nigella sativa against Ischemia-Reperfusion Injury of Kidneys

Background. Ischemia-reperfusion, commonly seen in the fields of trauma surgery and renal transplantation, is a major cause of acute kidney injury and is associated with significant morbidity and mortality. The protective effects of Nigella sativa against ischemia-perfusion damage to various organs have been previously documented. However, its protective effects on kidney tissue against ischemia-reperfusion injury are unclear. In this study, we aimed to examine the effect of Nigella sativa in modulating inflammation and apoptosis after renal I/R injury. Materials and methods. Thirty male Wistar-albino rats were divided into three groups: sham-operated, ischemia-reperfusion, and ischemia-reperfusion + Nigella sativa. Rats in the third group were given Nigella sativa 6 h prior to ischemia-reperfusion and at the beginning of reperfusion. All rats except those in the sham-operated group underwent 45 min of bilateral renal ischemia followed by 45 min of reperfusion. Blood samples and liver tissues were harvested from the rats, and then rats were sacrificed. Serum urea and creatinine levels were determined. Total antioxidant capacity (TAC), catalase (CAT), total oxidant status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO) in kidney tissue and blood were measured. Kidney tissue histopathology was also evaluated. Results. Nigella sativa was effective in reducing serum urea and creatinine levels as well as decreasing the tubular necrosis score. Nigella sativa treatment significantly reduced OSI and TOS levels and increased TAC levels in both kidney tissue and blood. Conclusion. The observed differences seem to demonstrate the protective effect of Nigella sativa against renal I/R injury in rat kidneys.     

Ameliorative Effects of Proanthocyanidin on Renal Ischemia/Reperfusion Injury

Introduction. Several natural products have been reported to have beneficial effects on ischemia/reperfusion (I/R) injury, particularly from a preventative perspective. Therefore, this study was designed to investigate the efficiency of proanthocyanidin (PA), a natural product derived from grape seed, on renal dysfunction and injury induced by I/R of rat kidney. Materials and Methods. Twenty-four male Sprague-Dawley rats were divided into three groups: sham-operated, I/R, I/R+PA. Rats were given PA (100 mg/kg/day peroral) 7 days prior to I/R. All rats except sham-operated underwent 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for evaluation. Superoxide dismutase, glutathione peroxidase, malondialdehyde, protein carbonyl content, and nitrite/nitrate level (NO_x) were determined in the renal tissue. Serum creatinine (S_Cr), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) were determined in the blood. Additionally, renal sections were used for histological grade of renal injury. Results. PA significantly reduced the I/R-induced increases in S_Cr, BUN, and AST. In addition, PA markedly reduced elevated oxidative stress product, restored decreased antioxidant enzymes, and attenuated histological alterations. Moreover, PA attenuated the tissue NO_x, levels indicating reduced NO production. Conclusions. The pretreatment of rats with PA reduced the renal dysfunction and morphological changes, ameliorated cellular injury, and restored renal antioxidant enzymes caused by renal I/R.     

3-Aminobenzamide,a Poly ADP Ribose Polymerase Inhibitor,Attenuates Renal Ischemia/Reperfusion Injury

Introduction. This study was designed to investigate whether 3-amino benzamide (3-AB), a poly (ADP-ribose) polymerase (PARP) inhibitor, has a protective effect on kidney injury induced by renal ischemia/reperfusion (I/R) by decreasing oxidative and nitrosative stress on renal dysfunction and injury. Materials and Methods. Thirty-two male Sprague-Dawley rats were divided into four groups: sham-operated, sham-operated + 3-AB, I/R, I/R + 3-AB. Rats were given 3-AB (100 mg/kg/day ip) 14 days prior to I/R. I/R and I/R + 3-AB groups underwent 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for evaluation. Superoxide dismutase, glutathione peroxidase, malondialdehide, protein carbonyl content, and nitrite/nitrate level (NO_x) were determined in the renal tissue. Serum creatinine (S_Cr), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) were determined in the blood. Additionally, renal sections were used for histological grade of renal injury. Results. 3-AB significantly reduced the I/R-induced increases in S_Cr, BUN, and AST. In addition, 3-AB markedly reduced elevated oxidative stress product, restored decreased antioxidant enzymes, and attenuated histological alterations. Moreover, 3-AB attenuated the tissue NO_x levels, indicating reduced NO production. Conclusions. 3-AB has beneficial effect on renal glomerular and tubular dysfunction in rats' kidneys subjected to I/R injury. Moreover, 3-AB has ameliorating effect on both oxidative stress and nitrosative stress of the kidneys, which correlated with histopathological evaluation.     

Effects of Intravenous Anesthetics on Renal Ischemia/Reperfusion Injury

Background. Renal ischemia/reperfusion (I/R)-induced tubular epithelial cell injury, called ischemic acute renal failure, is associated with high mortality in humans. Protecting the kidney against I/R injury is very important during complicated renal operations, transplantation surgery, and anesthesia. Aim. The purpose of this study was to investigate and compare the efficiency of ketamine, thiopental, propofol, etomidate, and intralipid in reducing the injury induced by free radicals in a rat model of renal I/R. Method. Forty-two Wistar rats were divided into seven groups in our study. Rats in the sham group underwent laparotomy and waited for 120 minutes (min) without ischemia. Rats in the control group were given nothing with ischemia-reperfusion. Rats in the I/R groups were given ketamine (20 mg/kg), thiopental (20 mg/kg) propofol (25 mg/kg), etomidate (10 mg/kg) and 10% intralipid (250 mg/kg) intraperitoneally 15 min prior to the ischemia for 60 min, followed by reperfusion for 60 min. The blood samples and kidney tissues of the rats were obtained under anesthesia at the end of the reperfusion period. Biochemical malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), blood urea nitrogen (BUN), creatine (Cr), aspartate aminotransferase (AST) were determined, and histopathological analysis was performed with these samples. Results. MDA level was increased significantly in the control group (p < 0.05). Histopathological findings of the control group confirmed that there was renal impairment by tubular cell swelling, interstitial edema, medullary congestion, and tubular dilatation. MDA levels were lower in the ketamine, thiopental, and propofol groups compared to the control group (p < 0.05). In the thiopental and propofol groups, the levels of histopathological scores were significantly lower than control and etomidate groups in ischemia-reperfusion. Conclusion. Our results demonstrated that I/R injury was significantly reduced in the presence of propofol and thiopental. The protective effects of these drugs may belong to their antioxidant properties. These results may indicate that propofol and thiopental anesthesia protects against functional, biochemical, and morphological damage better than control in renal I/R injury.     

Scavenging of Peroxynitrite Reduces Renal Ischemia/Reperfusion Injury

Introduction. Nitric oxide (NO) and peroxynitrite (OONO—) are implicated in the pathophysiology of renal ischemia/reperfusion (I/R). The aim of this study was to investigate and compare the efficiency of S-methylisothiourea (SMT), an iNOS inhibitor, and mercaptoethylguanidine (MEG), a scavenger of peroxynitrite, on renal dysfunction and injury induced by I/R of rat kidney. Materials and Methods. Thirty-two male Sprague-Dawley rats were divided into four groups: sham-operated, I/R, I/R+SMT, and I/R+MEG. Rats were given SMT (10 mg/kg ip) or MEG (10 mg/kg ip) 6 h prior to I/R and at the beginning of reperfusion. All rats except sham-operated underwent 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for evaluation. Superoxide dismutase, glutathione peroxidase, malondialdehide, protein carbonyl content, and nitrite/nitrate level (NO_x) were determined in the renal tissue. Serum creatinine (S_Cr), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) were determined in the blood. Additionally, renal sections were used for histological grade of renal injury. Results. SMT and MEG significantly reduced the I/R-induced increases in S_Cr, BUN, and AST. Both SMT and MEG attenuated the tissue NO_x levels, indicating reduced NO production. In addition, SMT and MEG markedly reduced elevated oxidative stress product, restored decreased antioxidant enzymes, and attenuated histological alterations. Interestingly, MEG exerted a greater renoprotective effect than SMT. Conclusions. These data support the finding that iNOS and peroxynitrite are involved in the renal I/R injury, and suggest that a scavenger of peroxynitrite might be more effective than iNOS inhibitors as a therapeutic intervention.     

Preconditioning with oxygen attenuates rat renal ischemia-reperfusion injury

BACKGROUND: Short time pretreatment with oxygen is reported to be protective against subsequent ischemia-reperfusion (IR) injury of heart and spinal cord in some animal models. The purpose of this study was to investigate the effects of pre-exposure to hyperoxic environment on rat renal IR injury for the first time. MATERIALS AND METHODS: The effects of 1 h/d pretreatment with oxygen (>or=95%) for 5 days on a right nephrectomized rat model of renal IR injury was investigated by comparing creatinine clearance, fractional excretion of sodium, plasma creatinine, blood urea nitrogen, and histological injury scores among three groups: IR (40 min ischemia-24 h reperfusion), sham (no IR), and hyperoxia (5 days intermittent pretreatment with oxygen + IR). RESULTS: Intermittent pretreatment with oxygen resulted in significant improvement of creatine clearance and fractional excretion of sodium (P 相似文献   

Hemolysate pretreatment ameliorates ischemic acute renal injury in rats

Heme oxygenase-1 (HO-1) is an antioxidant enzyme and is believed to protect against oxidative stress-induced tissue injury. Renal ischemia-reperfusion (IR) injury seems at least in part to be caused by the oxidative stress. The aim of this study was to improve the renal IR injury by clinically available means. When littermate hemolysate was intravenously administered into rats, HO-1 was markedly induced in the kidneys. To investigate whether prior induction of HO-1 by the hemolysate injection ameliorates the subsequent renal IR injury, we assessed the levels of blood urea nitrogen (BUN) and serum creatinine (SCr), markers for renal injury, in rats with 45 min of ischemia followed by 18 h of reperfusion. To avoid the nephrotoxicity induced by hemolysate, small but effective amounts of hemolysate was injected into rats at 48 h prior to the ischemia. The levels of BUN and SCr values were significantly improved as compared to the rats with renal IR injury alone. Administration of HO inhibitor abolished the efficacy of hemolysate pretreatment. Our findings indicated that the prior induction of HO-1 by treatment of littermate hemolysate ameliorated the subsequent renal IR injury. Prior injection of self-hemolysate would be clinically useful for the protection against the renal IR injury induced by kidney transplantation and kidney surgery without immunological and infectious problems.     

The protective effect of nesfatin-1 against renal ischemia–reperfusion injury in rats

Abstract

Introduction: The pathogenetic mechanisms underlying ischemia-reperfusion (I/R) injury involve oxidative stress, inflammation and apoptosis. Nesfatin-1, a novel peptide, has been reported to possess antioxidant, anti-inflammatory and anti-apoptic properties. The study was to examine the potential protective effects of nesfatin-1 on renal I/R injury. Materials and methods: I/R model was induced by placing a clamp across left renal artery for 45?min followed by 24?h reperfusion, along with a contralateral nephrectom. Twenty-four rats divided into three groups: sham-operated group, vehicle-treated I/R and nesfatin-1-treated I/R. Nesfatin-1 was intraperitoneally injected 30?min before renal ischemia. We harvested serum and kidneys at 24?h after reperfusion. Renal function and histological changes were assessed. Marker of oxidative stress and cells in kidney were also evaluated. Results: The animals with nesfatin-1 significantly improved renal functional and histologic lesions induced by I/R injury. The malondialdehyde (MDA) level decreased, whereas superoxide dismutase (SOD) and catalase (CAT) activities were significantly increased. Moreover, nesfatin-1-treated rats had a markedly decrease in apoptotic tubular cells, as well as a decrease in caspase-3 activity and an increase in the bcl-2/Bax ratio. Conclusions: This is the first evidence that nesfatin-1 treatment ameliorates acute renal I/R injury by suppressing oxidative stress and cell apoptosis. Therefore, it is promising as a potential therapeutic agent for renal IR injury.     

Hyperbaric oxygenation attenuates renal ischemia-reperfusion injury in rats

BACKGROUND: Oxygen-derived free radicals play an important role in ischemia-reperfusion injury (IR). Hyperbaric oxygenation (HO) decreases free radical production. The aim of this study was to determine the effect of HO treatment on renal ischemia-reperfusion injury in rats. METHODS: Rats were divided into four groups. All groups underwent right nephrectomy. Group I served as the control group; group II had left renal ischemia-reperfusion; group III was pretreated with HO; and group IV, ischemia-reperfusion and HO pretreatment. Tissue malondialdehyde (MDA) and glutathione (GSH) levels were measured, and histopathologic damage scored. RESULTS: HO pretreatment significantly decreased tissue MDA levels and histopathologic scores among rats with IR. There was an increased GSH in HO-pretreated rats with IR; however, the difference was not significant. CONCLUSION: HO prior to ischemia displayed a beneficial effect on renal IR by reducing oxygen radical peroxidation of lipid membranes.     

Pioglitazone protects against renal ischemia-reperfusion injury by enhancing antioxidant capacity

Background

In our previous study, we showed that pioglitazone exerts protective effects on renal ischemia-reperfusion injury (IRI) in mice by abrogating renal cell apoptosis. Oxidative stress due to excessive production of reactive oxygen species and subsequent lipid peroxidation plays a critical role in renal IRI. The purpose of the current study is to demonstrate the effect of pioglitazone on renal IRI by modulation of oxidative stress.

Materials and methods

IRI was induced by bilateral renal ischemia for 45 min followed by reperfusion. Thirty healthy male Balb/c mice were randomly assigned to one of the following groups: phosphate buffer solution (PBS) + IRI, pioglitazone + IRI, PBS + sham IRI, pioglitazone + sham IRI. Kidney function tests and kidney antioxidant activities were determined 24 h after reperfusion.

Results

Pretreatment with pioglitazone produced reduction in serum levels of blood urea nitrogen and creatinine caused by IRI. Pretreatment with pioglitazone before IRI resulted in a higher level of kidney enzymatic activities of superoxide dismutase, glutathione, catalase, and total antioxidant capacity than in the PBS-pretreated IRI group.

Conclusions

Our results indicate that pioglitazone can provide protection for kidneys against IRI by enhancing antioxidant capacity. Therefore, pioglitazone could be a potential therapeutic approach to prevent renal IRI relevant to various clinical conditions.     

Protective effect of rutin on testicular ischemia-reperfusion injury

Purpose

The pathophysiology of testicular torsion-detorsion is an ischemia-reperfusion injury caused by overgeneration of reactive oxygen species (ROS). This study aimed to investigate the effect of rutin, a well-known antioxidant, on testicular ischemia-reperfusion injury.

Methods

Sixty male Sprague-Dawley rats were randomly divided into 3 groups, each containing 20 rats. Rats in the control group underwent a sham operation of the left testis. In the torsion-detorsion group, the left testis was rotated 720° for 2 hours. Rats in the treatment group received the same surgical procedure as the torsion-detorsion group, but rutin was administered intravenously at the time of detorsion. Bilateral orchiectomy was performed on half of the rats in each experimental group at 4 hours after detorsion for measurement of malondialdehyde, an indicator of intratesticular ROS content, and for evaluation of superoxide dismutase and catalase, which are endogenous antioxidant enzymes. Orchiectomy was performed on the remaining rats at 3 months after detorsion for analysis of testicular spermatogenesis.

Results

Unilateral testicular torsion-detorsion caused a significant increase in malondialdehyde level and caused significant decreases in superoxide dismutase, catalase activities, and spermatogenesis in ipsilateral testes. The rats treated with rutin had a significant decrease in malondialdehyde level and had significant increases in superoxide dismutase, catalase activities, and spermatogenesis in ipsilateral testes, compared with torsion-detorsion group.

Conclusions

Rutin protects testes from ischemia-reperfusion injury. The protective effect of rutin may be caused by scavenging ROS by increasing superoxide dismutase and catalase activities.     

Inhibition of inducible nitric oxide synthase prevents shock wave therapy induced renal injury

Objectives: Shock wave lithotripsy treatment (SWT) is not completely free from side effects; one of the accused mechanisms for renal injury during SWT is oxygen- and nitrogen-derived free radical productions. Therefore, we aimed to evaluate the effect of inhibition of nitric oxide (NO) production by N-[3(aminomethyl) benzyl) acetamidine] (1400W), highly selective inducible nitric oxide synthase (iNOS) inhibitor, at SWT-induced kidney damage. Materials and methods: Twenty-four rats those underwent right nephrectomy procedure were divided equally into three groups as control, SWT, and SWT?+?1400W. 1400W was administered at a dose of 10?mg/kg at 2?h prior to SWT procedure and at the beginning of SWT procedure via intraperitoneal route and continued daily for consecutive 3 days. At the end of the fourth day, animals were killed via decapitation and trunk blood and the left kidneys were taken for biochemical and histopathologic evaluation. Results: SWT caused renal tubular damage and increased lipid peroxidation and antioxidant enzyme activities and SWT also significantly increased nitro-oxidative products. Inhibition of iNOS via administration of 1400W ameliorated renal injury and decreased tissue lipid peroxidation (malondialdehyde), superoxide dismutase, glutathione peroxidase and nitrite/nitrate levels (NO_x). In addition, it was seen that histolopathological changes were attenuated in the SWT?+?1400W group when compared to SWT group. Conclusion: SWT-induced renal injury might be due to excessive production of oxygen free radicals and NO production. Inhibition of iNOS attenuates renal injury following SWT treatment. It can be concluded that iNOS inhibitors or peroxynitrite scavengers might be used to protect the kidneys against SWT-induced morphological and functional injuries.     

Effect of U-74500A,a 21-aminosteroid on renal ischemia-reperfusion injury in rats

Renal ischemia-reperfusion injury constitutes the most common pathogenic factor for acute renal failure and is the main contributor to renal dysfunction in allograft recipients and revascularization surgeries. Many studies have demonstrated that reactive oxygen species play an important role in ischemic acute renal failure. The aim of the present study was to investigate the effects of the synthetic antioxidant U-74500A, a 21-aminosteroid in a rat model of renal ischemia-reperfusion injury. Renal ischemia-reperfusion was induced by clamping unilateral renal artery for 45 min followed by 24 h of reperfusion. Two doses of U-74500A (4.0 mg/kg, i.v.) were administered 45 min prior to renal artery occlusion and then 15 min prior to reperfusion. Tissue lipid peroxidation was measured as thiobarbituric acid reacting substances (TBARS) in kidney homogenates. Renal function was assessed by estimating serum creatinine, blood urea nitrogen (BUN), creatinine and urea clearance. Renal morphological alterations were assessed by histopathological examination of hematoxylin-eosin stained sections of the kidneys. Ischemia-reperfusion produced elevated levels of TBARS and deteriorated the renal function as assessed by increased serum creatinine, BUN and decreased creatinine and urea clearance as compared to sham operated rats. The ischemic kidneys of rats showed severe hyaline casts, epithelial swelling, proteinaceous debris, tubular necrosis, medullary congestion and hemorrhage. U-74500A markedly attenuated elevated levels of TBARS as well as morphological changes, but did not improve renal dysfunction in rats subjected to renal ischemia-reperfusion. These results clearly demonstrate the in vivo antioxidant effect of U-74500A, a 21-aminosteroid in attenuating renal ischemia-reperfusion injury.     

Effect of U-74500A,A 21-Aminosteroid on Renal Ischemia-Reperfusion Injury in Rats

Renal ischemia-reperfusion injury constitutes the most common pathogenic factor for acute renal failure and is the main contributor to renal dysfunction in allograft recipients and revascularization surgeries. Many studies have demonstrated that reactive oxygen species play an important role in ischemic acute renal failure. The aim of the present study was to investigate the effects of the synthetic antioxidant U-74500A, a 21-aminosteroid in a rat model of renal ischemia-reperfusion injury. Renal ischemia-reperfusion was induced by clamping unilateral renal artery for 45 min followed by 24 h of reperfusion. Two doses of U-74500A (4.0 mg/kg, i.v.) were administered 45 min prior to renal artery occlusion and then 15 min prior to reperfusion. Tissue lipid peroxidation was measured as thiobarbituric acid reacting substances (TBARS) in kidney homogenates. Renal function was assessed by estimating serum creatinine, blood urea nitrogen (BUN), creatinine and urea clearance. Renal morphological alterations were assessed by histopathological examination of hematoxylin-eosin stained sections of the kidneys. Ischemia-reperfusion produced elevated levels of TBARS and deteriorated the renal function as assessed by increased serum creatinine, BUN and decreased creatinine and urea clearance as compared to sham operated rats. The ischemic kidneys of rats showed severe hyaline casts, epithelial swelling, proteinaceous debris, tubular necrosis, medullary congestion and hemorrhage. U-74500A markedly attenuated elevated levels of TBARS as well as morphological changes, but did not improve renal dysfunction in rats subjected to renal ischemia-reperfusion. These results clearly demonstrate the in vivo antioxidant effect of U-74500A, a 21-aminosteroid in attenuating renal ischemia-reperfusion injury.     

Lycopene has reduced renal damage histopathologically and biochemically in experimental renal ischemia-reperfusion injury

Abstract

Background: The present study aimed to investigate whether the inflammatory and antioxidant lycopene has a therapeutic effect against renal ischemia/reperfusion (I/R) injury. Materials and methods: In this study, 24 Wistar-Albino rats, weighing from 200 to 250?g, were divided into four groups. All rats underwent median laparotomy under anesthesia. No procedures were performed in the control group (Group C), whereas 100?mg/kg lycopene was administered by gavage in the lycopene group (Group L). The arteries of both kidneys were clamped for 45?min in the ischemia group (Group I), whereas 100?mg/kg lycopene was administered by gavage 30?min before clamping renal arteries, and ischemia was performed in the treatment group (Group T) rats. For all rats, blood samples and renal tissues were collected at 6?h of reperfusion. Samples were used to examine serum BUN, creatinine, MDA and GSH levels, and the renal tissues were used to examine MDA and GSH levels, and renal histopathologies. Results: The treatment group had statistically significant lower serum MDA levels, histopathological tubular vacuolization, loss of brush border and tubular dilatation (p?<?0.05), whereas serum BUN, creatinine, tissue MDA, and tissue and serum GSH levels were improved in favor of the treatment group, even though it was not statistically significant (p?>?0.05). Conclusion: The present study demonstrated that lycopene, which was administered prior to renal I/R injury, prevented renal damage through biochemical and histopathological parameters.     

Pretreatment with Pentoxifylline and N-Acetylcysteine in Liver Ischemia Reperfusion-Induced Renal Injury

Background and Aims: Acute hepatic injury causes systematic inflammatory responses which may finally lead to functional disturbances in remote organs. In this study, the effects of an inhibitor of inflammatory cytokines (pentoxifylline, PTX) and a well-known antioxidant, N-acetylcysteine (NAC), were evaluated on renal damage and oxidative stress following liver ischemia reperfusion (IR). Method: Five groups of six male rats were used. Group 1 was sham operated. In group 2, 90 min liver partial ischemia was induced by a clamp around both hepatic artery and portal vein and then followed by 4 h of reperfusion. In groups 3 and 4, PTX or NAC was injected intraperitoneally before the ischemia, while in group 5 both drugs were co-administered. The levels of alanine amino-transferase (ALT), aspartate amino-transferase (AST), blood urea nitrogen (BUN), and creatinine in serum as well as malonyldialdehyde (MDA) and glutathione (GSH) levels and morphological changes in renal tissues were assessed. Results: Significant increase in the serum levels of ALT and AST in IR group is indicative of liver functional damages. Elevated BUN and renal tissue MDA, decreased GSH levels, and morphological damages in IR group demonstrate a significant kidney injury and oxidative stress comparing to sham group. Administration of PTX alone and PTX + NAC prevented the IR-induced increase in renal MDA levels. Administration of both drugs and their co-administration prevented the reduction in renal GSH levels and morphological changes. Conclusion: Pretreatment with PTX and NAC before liver IR may be useful to ameliorate renal oxidative damage by preservation of cellular GSH concentration and a reduction in MDA levels.     

Re-Protective Effects of Pre- and Post-Laparoscopy Conditioning,Zinc, Pentoxifylline,and N-acetylcysteine in an Animal Model of Laparoscopy-Induced Ischemia/Reperfusion Injury of the Kidney

Background. Pneumoperitoneum (P) created to facilitate laparoscopy (L) is associated with splanchnic hypoperfusion, ischemia/reperfusion (I/R) injury, and oxidative stress. Aim. This study investigated the effects of pre- and post-laparoscopic conditioning, zinc, pentoxifylline (PTX), and N-acetylcysteine (NAC) on markers of I/R injury in an animal model. Methods. Sprague-Dawley male rats (n?=?56, weight range 300–350 g) were randomly placed in one of seven treatment groups. Except for group C (control group who underwent a sham operation without pneumoperitoneum), pneumoperitoneum was created in all using CO₂ insufflation under a pressure of 15 mmHg. Group L (laparoscopy) was subjected to 60 min of pneumoperitoneum. Group Lpre (laparoscopic preconditioning plus laparoscopy) was subjected to 5 min of insufflation and 5 min of desufflation followed by 60 min of pneumoperitoneum. Group Lpost (laparoscopy plus laparoscopic post-conditioning) was subjected to 60 min of pneumoperitoneum and 60 min of desufflation followed by 5 min of insufflation and 5 min of desufflation. The laparoscopy plus zinc (LZ), PTX (LP), and NAC (LNAC) groups received a single intraperitoneal injection of zinc (50 mg/kg), pentoxifylline (50 mg/kg), or N-acetylcysteine (150 mg/kg) 5 min before the desufflation period. Animals were sacrificed at the end of the experiments, and kidney samples were tested for malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). Results. MDA levels, as an indicator of oxidative stress in kidney tissue samples, were significantly higher in all pneumoperitoneum groups compared to Group C, except for Group Lpre. The pattern of change in tissue levels of SOD, GPX, and catalase was variable in the different treatment groups. Conclusions. In this animal model of renal ischemia/reperfusion injury, laparoscopy caused renal ischemia as evidenced by elevated markers of tissue ischemia-reperfusion injury. This effect was significantly attenuated by post-laparoscopy conditioning, zinc, pentoxifylline, and N-acetylcysteine, but not by pre-laparoscopy conditioning.     

Effects of Everolimus on Cytokines,Oxidative Stress,and Renal Histology in Ischemia-Reperfusion Injury of the Kidney

Background. To evaluate the effects of everolimus on renal ischemia-reperfusion injury (IRI). Methods. Wistar albino rats were divided into control, ischemia-reperfusion (IR), and ischemia-reperfusion/everolimus (IR/eve) groups. Everolimus was administered for seven consecutive days to the IR/eve group prior to injury. IR and IR/eve groups underwent forty-five minutes ischemia followed by the application of reperfusion at 2 and 24 hours. Blood samples and kidneys were taken from all animals. Results. Serum blood urea nitrogen and creatinine levels increased at two hours of reperfusion in the IR and IR/eve groups, and decreased at 24 hours of reperfusion in the IR group. In the IR/eve group, we detected significantly high interleukin-6 levels and low tumor necrosis factor-α and malondialdehyde levels at 24 hours. Myeloperoxidase levels increased at two hours of reperfusion in the IR/eve group, but decreased significantly at 24 hours. Everolimus did not improve renal tubular and interstitial injuries in renal IRI. Conclusions. It has been demonstrated that pretreatment with everolimus has beneficial effects on cytokines and oxidative stress in renal IRI. However, these effects are insufficient for the correction of histopathological changes and restoration of normal kidney function.     

Attenuation of hyperoxic lung injury in rabbits with superoxide dismutase: effects on inflammatory mediators

Background. Superoxide dismutase (SOD) has been shown to attenuate hyperoxic lung injury. This effect is thought to be exhibited by scavenging superoxide released from neutrophils and other aerobic cells. The aim of the current study was to investigate the effect of pre-treatment with SOD on the chemical mediators in hyperoxic lung injury. Methods. Thirty male anesthetized rabbits were allocated to receive one of three treatments (n = 10 for each group): ventilated with 100% oxygen for 36 h with or without recombinant human SOD (rhSOD) treatment, and ventilated with air for 36 h without rhSOD. In the rhSOD-treated group, a single intravenous dose of rhSOD 10,000 U kg BW^-1 was administered immediately after the start of exposure to 100% oxygen and thereafter infused at a rate of 340,000 U kg BW^-1 day^-1 for 36 h until the animals were sacrificed. The lungs of all rabbits were ventilated with 100% oxygen or air. Haemodynamics, Pao₂, and lung mechanics were recorded during the ventilation period. After exposure to 100% oxygen, lung mechanics, cell fraction of bronchoalveolar lavage fluid (BALF), activated complements, cytokines, and arachidonic acid metabolite concentrations in BALF were measured and analyzed. The lung wet-to-dry (W/D) weight ratio and albumin concentrations in BALF were determined as indices of pulmonary oedema. Results. Exposure to the high concentration of oxygen for 36 h caused no significant changes in haemodynamics but decreased compliance and increased A-aDo₂. In the rhSOD-treated group, the decrease in compliance was not observed. At the end of the 36 hrexposure period, however, hyperoxia significantly increased the lung W/ D weight ratio, influx of neutrophils into the lung, BALF concentrations of C3a, C5a, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, thromboxane B₂, and albumin. Pre-treatment with rhSOD attenuated these increases. Exposure to 100% oxygen caused extensive morphologic lung damage (alveolar haemorrhage and hyaline membrane formation), which was lessened by rhSOD. Conclusion. These results indicate that intravenous rhSOD prevented hyperoxic lung injury (decreases in Pao₂ and compliance, increased pulmonary vascular permeability, histopathological damage) in rabbits. This prophylactic effect of rhSOD amy be due, in part, to decreased chemical mediators such as activated complements, cytokines, and arachidonic acid metabolites.     

氧葡萄糖血清剥夺/再恢复诱导PC12细胞凋亡模型的建立

目的明确氧葡萄糖血清剥夺/再恢复(oxygen-glucose-serum deprivation/restoration,OGSD/R)诱导PC12细胞凋亡的变化趋势,建立稳定的细胞凋亡模型,为体外模拟脊髓缺血再灌注损伤导致神经细胞凋亡的研究提供实验工具。方法常规培养高分化PC12细胞,取对数生长期的细胞进行实验。以低糖不含血清的DMEM培养基于三气培养瓶(体积分数:95%N_2+5%CO_2,O_21%)培养12 h,然后换成高糖含血清DMEM培养基和普通培养箱继续培养,诱导PC12细胞凋亡。于复氧复糖复血清后0~6 h进行DAPI染色、CCK-8细胞活性检测及流式细胞术分析并检测相关凋亡蛋白caspase-3、caspase-12水平,比较不同时间点细胞凋亡的差异。结果 DAPI染色显示,OGSD 12 h/R 1 h细胞凋亡最重,凋亡细胞核固缩,形成较多颗粒光斑,凋亡严重的细胞破裂形成碎片,核解体。CCK-8活性检测表明在OGSD 12 h/R 1 h细胞活力最低。流式细胞术分析表明OGSD 12 h/R 1 h细胞凋亡率达到最大。凋亡蛋白检测结果提示在正常的PC12细胞中caspase-3、caspase-12含量极低,而在给予OGSD刺激后细胞内caspase-3、caspase-12的表达增强,复氧复糖复血清后2种凋亡蛋白表达进一步增强,caspase-12于OGSD 12 h/R 1 h时表达最强,caspase-3于OGSD 12 h/R 2 h表达最强。结论 OGSD可以诱导PC12细胞凋亡,且在复氧复糖复血清后细胞凋亡进一步加重;OGSD/R诱导PC12细胞凋亡具有时间依赖性,能有效模拟神经细胞缺血再灌注损伤病理生理过程,为脊髓缺血再灌注损伤的进一步研究提供实验模型。