The effects of resveratrol administration on lipid oxidation in experimental renal ischemia-reperfusion injury in rats

ABSTRACT

We investigated how resveratrol affects lipid oxidation during experimental renal ischemia-reperfusion injury in rats. We used 48 adult male rats assigned to five groups: group 1, control; group 2, renal ischemia; group 3, renal ischemia + reperfusion; group 4, resveratrol + renal ischemia; group 5, resveratrol + renal ischemia + reperfusion. Plasma and renal tissue malondialdehyde (MDA), and erythrocyte and renal tissue glutathione (GSH) levels were measured and histologic changes in the renal tissue were examined. Ischemia-reperfusion affected the MDA-GSH balance adversely and caused histopathological changes in the renal tissue of the ischemia and ischemia + reperfusion groups. Resveratrol treatment normalized MDA and GSH levels as well as the histopathology that occurred in the renal tissue of the ischemia and ischemia + reperfusion groups.     

Protective effects of doxycycline in ischemia/reperfusion injury on kidney

Renal ischemia and reperfusion injury is the major cause of acute renal failure and may also be involved in the development and progression of some forms of chronic kidney disease. The aim of this study was to evaluate whether doxycycline, a member of the tetracycline family of antibiotics, protects kidney tissue or not. 36 Sprague-Dawley rats (200–250 g) were used. The animals were divided into three groups: control, ischemia/reperfusion and ischemia/reperfusion+doxycycline group. Rats were subjected to renal ischemia by clamping the left pedicle for 1 h, and then reperfused for 1 h. The ischemia/reperfusion+doxycycline group were pretreated intraperitoneally with doxycycline suspension (10 mg/kg) 2 h before the induction of ischemia. Our results indicate that malondialdehyde, matrix-metalloproteinase-2, interleukin-2, interleukin-6, interleukin-10, interleukin 1-beta and tumor necrosis factor-alpha levels were significantly higher in the ischemia/reperfusion group than those in the control group. Doxycycline administration significantly decreased these parameters. Tissue inhibitor of metalloproteinases-1 levels also increased after ischemia/reperfusion and decreased with doxycycline pretreatment, but these changes were not significantly different. Glutathione levels significantly decreased after ischemia/reperfusion injury when compared with the control group and doxycycline pretreatment significantly increased glutathione levels when compared with the ischemia/reperfusion group. Apoptotic cells and p53 positive cells were significantly decreased in doxycycline treated group. These results suggest that doxycycline reduces renal oxidative injury and facilitates repair. Doxycycline may play a role in a renoprotective therapeutic regimen.     

巨噬细胞亚型转变在大鼠肾脏缺血/再灌注损伤中的作用

目的：探讨巨噬细胞在大鼠肾脏缺血/再灌注损伤过程中的亚型转变及意义。方法：将30只雄性SD大鼠随机分成假手术组（Sham,n=6）和缺血/再灌组（IRI,夹闭肾动脉45 min,n=24）。IRI组分别于术后0、6、24和72 h取肾组织,每个时相组6只大鼠。用HE染色观察肾组织损伤程度;免疫组化染色检测细胞增殖核抗原（PCNA）的表达;实时定量RT-PCR检测巨噬细胞移动抑制因子（MIF） mRNA的表达;免疫组织荧光染色检测MIF、单核巨噬细胞趋化蛋白-1（MCP-1）以及活化巨噬细胞标志物CD68的表达,流式细胞分析检测巨噬细胞M1和M2亚型的分布特征。结果：病理结果显示大鼠肾局部损伤情况和炎症细胞浸润程度在24 h时最为严重,之后逐渐恢复。PCNA在再灌后表达明显增加,6 h达峰值,72 h表达下降。相比于正常组,再灌组大鼠肾组织中MIF的mRNA和蛋白表达明显升高;MCP-1表达则在6 h达峰值,随后下降;而CD68阳性的巨噬细胞数量明显增加,24 h达峰值,72 h表达下降。更进一步研究发现缺血/再灌注6 h时,M1亚型分布达最高值;之后随着缺血/再灌注时间延长,M1亚群相对含量开始下调,M2随之升高。结论：在肾脏缺血/再灌注早期,M1巨噬细胞介导的组织损伤发挥主要作用,随后M2型表达逐渐上调,并通过促进细胞增殖修复肾组织损伤。     

Cordyceps sinensis protects against renal ischemia/reperfusion injury in rats

Cordyceps sinensis (CS) is an entomogenous fungus used as a tonic food and Chinese medicine to replenish health. This study investigated the protective effects of CS in rats post-renal ischemia–reperfusion (I/R) sequence by analyzing the influence on stromal cell-derived factor-1α (SDF-1α and chemokine (C-X-C motif) receptor 4 (CXCR4) expressions and senescence during recovery. Chemokine SDF-1 [now called chemokine C-X-C motif ligand 12 (CXCL12)] and its receptor CXCR4 are crucial in kidney repair after ischemic acute renal failure. CS treatment significantly alleviated I/R-induced renal damage assessed by creatinine levels (p < 0.05) and abated renal tubular damages assessed by periodic acid-Schiff with diastase (PASD) staining. CS induced early SDF-1α expression and increased CXCR4 expression 1–6 h post-reperfusion. Histology studies have revealed that CS induced SDF-1α in squamous cells of Bowman’s capsule, mesangial cells, distal convoluted tubules (DCT), and proximal convoluted tubules (PCT). CS also improved renal repair in I/R-induced injury by increasing Ki-67 staining. I/R induced renal senescence after 3 and 6 h of reperfusion. However, CS alleviated I/R-induced senescence at early stage (1 and 3 h). We conclude that CS protects against I/R injury via the SDF-1/CXCR4-signaling axis and alleviates senescence.     

SP600125, a selective JNK inhibitor, protects ischemic renal injury via suppressing the extrinsic pathways of apoptosis

Accumulating evidence suggests that c-Jun N-terminal kinase (JNK) signaling pathway plays a critical role in renal ischemia/reperfusion injury. However, the downstream mechanism that accounts for the proapoptotic actions of JNK during renal ischemia/reperfusion has not been elucidated. We report that SP600125, a potent, cell-permeable, selective, and reversible inhibitor of c-Jun N-terminal kinase (JNK), potently decreased renal epithelial tubular cell apoptosis induced by renal ischemia/reperfusion via suppression of the extrinsic pathway. This corresponds to the decrease in JNK phosphorylation at 20 min and c-Jun phosphorylation (Ser63/73) at 3 h after renal ischemia. Additionally, SP600125 attenuated the increased expression of FasL induced by ischemia/reperfusion at 3 h. The administration of SP600125 prior to ischemia was also protective. Thus, our findings imply that SP600125 can inhibit the activation of the JNK-c-Jun-FasL pathway and protect renal tubular epithelial cells against ischemia/reperfusion-induced apoptosis. Taken together, these results indicate that targeting the JNK pathway provides a promising therapeutic approach for renal ischemia/reperfusion injury.     

The effects of desferrioxamine and quercetin on hepatic ischemia-reperfusion induced renal disturbance

BACKGROUND: The aim of this study was to analyze the effects of 45min of hepatic ischemia and 1h of reperfusion on renal oxidative stress parameters, on renal tissue damage, and the role of Desferrioxamin (Dfx) and Q on these parameters. METHODS: Thirty Wistar albino rats were randomized to five groups. Group I was the control group. Group II received no treatment. Groups III and IV received intramuscular injections of desferrioxamine (100mg/kg) and quercetin (50mg/kg), respectively. Group V was administered Dfx and quercetin in combination. After treatment for 3 days, groups II, III, IV, and V were exposed to total hepatic ischemia for 45min. Plasma alanine aminotransferase levels, renal malondialdehyde and reduced glutathione (GSH) activities were measured after reperfusion for 1h. Histopathological and ultrastructural analysis of renal tissues was carried out. RESULTS: Plasma creatinine and BUN levels were markedly increased in the IR group and pretreated groups. Kidney MDA increased in the IR group, Q and Dfx+Q significantly decreased kidney MDA Kidney GSH levels markedly decreased in the IR group, Dfx significantly increased kidney GSH. No evidence of overt injury was observed in any renal tissue under light and electron microscopy. CONCLUSIONS: Our data demonstrated that 45min of hepatic ischemia and 1h of reperfusion may alter renal functions and may cause oxidative stress on renal tissue. Q and Dfx seem to have a beneficial effect via the GSH system and modulation of MDA levels.     

心肌缺血／再灌注损伤后血清和心肌组织Leptin水平的变能

目的：观察大鼠心肌缺血／再灌注损伤对血清和心肌组织瘦素（Leptin）表达的影响,探讨Leptin在心肌缺血／再灌注损伤中的作用。方法：建立大鼠心肌缺血／再灌注模型,检测血清乳酸脱氢酶（LDH）和Leptin浓度,并用HE染色和免疫组织化学观察心肌组织病理学及Lepfin表达水平。结果：缺血组、再灌注组血清LDH水平显著升高（P〈0．05）,表明该模型制作成功,造成心肌局部一定程度的损伤。缺血组血清Leptin含量（6．34±2．49）ng／ml显著低于对照组（7．50±2．93ng／ml,P〈0．05）;再灌注后Leptin水平缓慢恢复,于再灌注2h时Leptin达到（8．32±1．74）ng／ml,恢复到损伤前水平（8．38±2．56）ng／ml,且随再灌注时间延长有升高趋势。免疫纽化显示与假手术纽心肌Leptin蛋白表达水平相比,其他四组均有显著降低（P〈0．01）,按缺血45min后再灌注1h组、缺血45min后再灌注3h组、单纯缺血45min组、缺血45min后再灌注2h组依次递减。结论：Leptin在心肌缺血／再灌注损伤后早期45min血中有明显减少,心肌组织中也明显表达下降。心肌组织病理损伤与Leptin的改变可能有一定的关系。     

The effects of PDE5 inhibitory drugs on renal ischemia/reperfusion injury in rats

The aim of the present study was to evaluate the effects of phosphodiesterase type 5 (PDE5) inhibitory drugs, Tadalafil and Sildenafil, on inducible NOS (iNOS), endothelial NOS (eNOS) and p53 genes expressions and apoptosis in ischemia/reperfusion (I/R) induced oxidative injury in rat renal tissue. Eighty Sprague-Dawley rats (300-350?g) were divided into four groups. In ischemia/reperfusion group, rats were subjected to renal ischemia by clamping the left pedicle for 60?min, and then reperfused for 90?min. On the other hand, in other two groups the rats were individually pretreated with Tadalafil and Sildenafil 1?h before the induction of ischemia. Malondialdehyde (MDA) is determined in renal tissue homogenates by high-performance liquid chromatography, the number of apoptotic cell were calculated by TUNEL method and p53 and eNOS expression were detected with immunohistochemistry. On the other hand, myeloperoxidase (MPO) levels were measured by spectrophotometric method and the mRNA level of iNOS in renal tissue was determined by Real-time PCR (RT-PCR). Our results indicate that MDA and MPO levels were increased in the I/R group than those in the control group. Both Tadalafil and Sildenafil treatment decreased the MDA levels in ischemia/reperfusion group, whereas this effect was more potent with Sildenafil. RT-PCR results showed that, iNOS gen expression increased in the I/R group, but decreased in the PDE5 inhibitory drugs treated group. Apoptotic cells, eNOS levels and p53 positive cells were also decreased in PDE5 inhibitory drugs treated group. We suggest that Tadalafil and Sildenafil have beneficial effects against I/R related renal tissue injury and this protective effect is clearer for Sildenafil than Tadalafil.     

The effect of quercetin on renal ischemia and reperfusion injury in the rat

Renal ischemia-reperfusion injury occurs in many clinical conditions such as hypovolemic shock, thromboembolism, injury and after renal transplantation. Under these conditions, ROS are considered to be the reason for cellular damage. Bioflavonoids have antioxidant and renoprotective properties. We studied the effect of quercetin, a bioflavonoid, on ischemia and reperfusion in rats. The rats (n = 28) were separated into three groups. Group I was the control group. Animals in groups II (IR) and III (IR + Q) underwent 30 min ischemia and 45 min reperfusion, respectively. Rats, in group III, also received 50 mg kg(-1) quercetin before 45 min of reperfusion. The activities of SOD, CAT, GPx, and concentrations of GSH and GSSGR were determined in renal cortex and erythrocytes. Also, the levels of MDA in renal cortex and plasma, and XO in renal cortex were measured in these groups. The renal cortex XO levels in the IR group were higher than that of the control and IR+Q groups (p<0.001). The renal cortex and plasma MDA levels in the IR group were also found to be higher than the control and IR+Q groups (p<0.01, and p<0.001, respectively). However, a decrease in MAD level of the IR+Q group was found in renal cortex and erythrocytes. In addition, SOD, CAT, and GPx activities in renal cortex and erythrocytes of quercetin-treated animals were enhanced compared to animals of the IR group. Furthermore, there were no significant differences in the SOD, CAT, and GPx activities of the control and IR+Q group. A reduction of GSH and GSSGR levels in IR and IR+Q groups was detected but no significant differences were found between these groups. This study stresses that high concentration of ROS leads to renal ischemia and reperfusion, and quercetin reduces the renal injury by preventing the oxidative stress dependent on ischemia and reperfusion. Quercetin may be used in renal transplantation as an antioxidant drug.     

Activation of hypoxia-inducible factor-1 ameliorates postischemic renal injury via inducible nitric oxide synthase

Hypoxia-inducible factor-1 (HIF-1) could ameliorate renal ischemia reperfusion injury (IRI), but the underlying mechanism remains elusive. In the current study, we aim to investigate the possible role of prolyl hydroxylases inhibitor dimethyloxalylglycine (DMOG) in inducing delayed preconditioning-like effects against IRI. Mice were divided into four groups (n = 6): sham group; IRI group; DMOG group: pretreated with DMOG 24 h before IRI; and GW274150 + DMOG group: pretreated with DMOG followed by iNOS inhibitor GW274150 treatment 24 h before IRI. The results showed that the protein level of HIF-1a and the expression of its targets inducible nitric oxide synthase (iNOS), erythropoietin, and heme oxygenase-1 were obviously increased after administration of DMOG. Histological analysis of renal function showed improvement in tubulointerstitial injury due to ischemia by delayed preconditioning with DMOG. GW274150 antagonized the delayed renal protection afforded by DMOG as reflected by deteriorated renal dysfunction, aggravated histological injury, increased renal cell apoptosis, and increased vimentin expression in the kidney. In conclusion, our data demonstrate that DMOG pretreatment induces delayed renal protection against IRI in mice and the beneficial effects are mitigated by pharmacological inhibition of iNOS, suggesting that the protective effects derived from HIF-1 activation via DMOG in the kidney are partially mediated by iNOS.     

No Effect of Remote Ischemic Conditioning Strategies on Recovery from Renal Ischemia-Reperfusion Injury and Protective Molecular Mediators

Ischemia-reperfusion injury (IRI) is the major cause of acute kidney injury. Remote ischemic conditioning (rIC) performed as brief intermittent sub-lethal ischemia and reperfusion episodes in a distant organ may protect the kidney against IRI. Here we investigated the renal effects of rIC applied either prior to (remote ischemic preconditioning; rIPC) or during (remote ischemic perconditioning; rIPerC) sustained ischemic kidney injury in rats. The effects were evaluated as differences in creatinine clearance (CrCl) rate, tissue tubular damage marker expression, and potential kidney recovery mediators. One week after undergoing right-sided nephrectomy, rats were randomly divided into four groups: sham (n = 7), ischemia and reperfusion (IR; n = 10), IR+rIPC (n = 10), and IR+rIPerC (n = 10). The rIC was performed as four repeated episodes of 5-minute clamping of the infrarenal aorta followed by 5-minute release either before or during 37 minutes of left renal artery clamping representing the IRI. Urine and blood were sampled prior to ischemia as well as 3 and 7 days after reperfusion. The kidney was harvested for mRNA and protein isolation. Seven days after IRI, the CrCl change from baseline values was similar in the IR (δ: 0.74 mL/min/kg [-0.45 to 1.94]), IR+rIPC (δ: 0.21 mL/min/kg [-0.75 to 1.17], p > 0.9999), and IR+rIPerC (δ: 0.41 mL/min/kg [-0.43 to 1.25], p > 0.9999) groups. Kidney function recovery was associated with a significant up-regulation of phosphorylated protein kinase B (pAkt), extracellular regulated kinase 1/2 (pERK1/2), and heat shock proteins (HSPs) pHSP27, HSP32, and HSP70, but rIC was not associated with any significant differences in tubular damage, inflammatory, or fibrosis marker expression. In our study, rIC did not protect the kidney against IRI. However, on days 3–7 after IRI, all groups recovered renal function. This was associated with pAkt and pERK1/2 up-regulation and increased HSP expression at day 7.     

Vitamin D Deficiency Aggravates Chronic Kidney Disease Progression after Ischemic Acute Kidney Injury

Background

Despite a significant improvement in the management of chronic kidney disease (CKD), its incidence and prevalence has been increasing over the years. Progressive renal fibrosis is present in CKD and involves the participation of several cytokines, including Transforming growth factor-β1 (TGF-β1). Besides cardiovascular diseases and infections, several studies show that Vitamin D status has been considered as a non-traditional risk factor for the progression of CKD. Given the importance of vitamin D in the maintenance of essential physiological functions, we studied the events involved in the chronic kidney disease progression in rats submitted to ischemia/reperfusion injury under vitamin D deficiency (VDD).

Methods

Rats were randomized into four groups: Control; VDD; ischemia/reperfusion injury (IRI); and VDD+IRI. At the 62 day after sham or IRI surgery, we measured inulin clearance, biochemical variables and hemodynamic parameters. In kidney tissue, we performed immunoblotting to quantify expression of Klotho, TGF-β, and vitamin D receptor (VDR); gene expression to evaluate renin, angiotensinogen, and angiotensin-converting enzyme; and immunohistochemical staining for ED1 (macrophages), type IV collagen, fibronectin, vimentin, and α-smooth mucle actin. Histomorphometric studies were performed to evaluate fractional interstitial area.

Results

IRI animals presented renal hypertrophy, increased levels of mean blood pressure and plasma PTH. Furthermore, expansion of the interstitial area, increased infiltration of ED1 cells, increased expression of collagen IV, fibronectin, vimentin and α-actin, and reduced expression of Klotho protein were observed. VDD deficiency contributed to increased levels of plasma PTH as well as for important chronic tubulointerstitial changes (fibrosis, inflammatory infiltration, tubular dilation and atrophy), increased expression of TGF-β1 and decreased expression of VDR and Klotho protein observed in VDD+IRI animals.

Conclusion

Through inflammatory pathways and involvement of TGF-β1 growth factor, VDD could be considered as an aggravating factor for tubulointerstitial damage and fibrosis progression following acute kidney injury induced by ischemia/reperfusion.     

Prevention of ischemia-reperfusion injury in rat ovarian tissue with the on-off method

Ischemia is defined as cell death caused by insufficient perfusion of the tissue due to reduction in arterial or venous blood flow, depletion of cellular energy storages, and accumulation of toxic metabolites. The positive effects of controlled reperfusion are known and are used clinically. But the positive effects of controlled reperfusion on ovarian tissue have not been seen in the literature yet. The biochemical and histopathological comparative investigation of rat ovaries that were experimentally exposed to ischemia (IG), ischemia-reperfusion (I/R), and ischemia-controlled reperfusion (ICR) was aimed. Forty rats were divided into four groups (10 rats per group). First group: 3 h ischemia by vascular clips on ovarian tissue. Second group: 3 h ischemia + 1 h reperfusion. Third group: 3 h ischemia + 1 h controlled reperfusion (on-off method: controlled reperfusion by opening and closing the clips (on/off) in 10-second intervals, for 5 times for a total of 100 seconds). Fourth group: healthy rats. Biochemical (tGSH, MDA, and DNA damage level and SOD activity) and histopathological analysis were performed. The highest glutathione and superoxide dismutase measurements were found in ischemia/controlled reperfusion group among the ischemia or ischemia/reperfusion groups. Similarly the damage indicators (malondialdehyde, DNA damage level and histopathological damage grade) were the lowest in ischemia/controlled reperfusion group. These results indicate that controlled reperfusion can be helpful in minimizing ischemia-reperfusion injury in ovarian tissue exposed to ischemia for various reasons (ovarian torsion, tumor, etc.).     

Detection of early stages of apoptosis in experimental intestinal ischemia-reperfusion injury

Apoptosis is a form of programmed cell death that plays an important role in small intestine ischemia-reperfusion (IR) injury. The aim of this study was to determine the total proportion of apoptotic cell death (apoptotic index) following injury induced by ischemia and during various subsequent reperfusion periods, total histopathological status and the intestine regeneration dynamics after the IR injury. Experimental animals, Wistar rats (n = 45) were divided into three experimental and one control groups. In the experimental groups 1 h ischemia was followed by 1, 4 and 24 h reperfusion. Intestinal ischemia was induced by superior mesenteric artery (SMA) occlusion. Segments of jejunum were stained with hematoxylin and eosin and studied immunohistochemically using M30 CytoDEATH and in situ TUNEL methods for apoptosis detection. Our experimental data showed that: (i) apoptosis is an important form of cell death in the small intestine after IR injury induced by SMA occlusion; (ii) maximum levels of histopathological damage and apoptotic index of mucosa occurred after 1 h ischemia and 1 h of reperfusion; and (iii) mucosa possesses great regeneration ability. The lowest levels of histopathological damage and apoptotic index were observed in the group with 1 h ischemia and 24 h reperfusion where, however, the highest mitotic index was present.     

Autophagy activation attenuates renal ischemia-reperfusion injury in rats

Ischemia-reperfusion (I/R) injury is a leading cause of acute kidney injury (AKI), which is a common clinical complication but lacks effective therapies. This study investigated the role of autophagy in renal I/R injury and explored potential mechanisms in an established rat renal I/R injury model. Forty male Wistar rats were randomly divided into four groups: Sham, I/R, I/R pretreated with 3-methyladenine (3-MA, autophagy inhibitor), or I/R pretreated with rapamycin (autophagy activator). All rats were subjected to clamping of the left renal pedicle for 45 min after right nephrectomy, followed by 24 h of reperfusion. The Sham group underwent the surgical procedure without ischemia. 3-MA and rapamycin were injected 15 min before ischemia. Renal function was indicated by blood urea nitrogen and serum creatinine. Tissue samples from the kidneys were scored histopathologically. Autophagy was indicated by light chain 3 (LC3), Beclin-1, and p62 levels and the number of autophagic vacuoles. Apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method and expression of caspase-3. Autophagy was activated after renal I/R injury. Inhibition of autophagy by 3-MA before I/R aggravated renal injury, with worsened renal function, higher renal tissue injury scores, and more tubular apoptosis. In contrast, rapamycin pretreatment ameliorated renal injury, with improved renal function, lower renal tissue injury scores, and inhibited apoptosis based on fewer TUNEL-positive cells and lower caspase-3 expression. Our results demonstrate that autophagy could be activated during I/R injury and play a protective role in renal I/R injury. The mechanisms were involved in the regulation of several autophagy and apoptosis-related genes. Furthermore, autophagy activator may be a promising therapy for I/R injury and AKI in the future.     

钙网蛋白参与缺血后处理减轻大鼠骨骼肌缺血/再灌注损伤

本实验分别在整体和细胞水平观察缺血后处理（ischemic postconditioning,I-postC）对骨骼肌缺血／再灌注（ischemia／reperfusion,I／R）损伤的影响,并探讨钙网蛋白（calreticulin,CRT）介导的信号转导机制。（1）整体实验：健康雄性Wistar大鼠48只,无创动脉夹夹闭右侧股动脉4h,松夹再灌注12h或24h建立大鼠右后肢I／R损伤模型,随机分为I／R组、缺血预处理（ischemic preconditioning,IPC）组（5min缺血／5min再灌,3个循环）和I-postC组（1min再灌／1min缺血,3个循环）（n=16）,大鼠左后肢做对照处理。再灌注结束时测定血浆乳酸脱氢酶（1actate dehydrogenase,LDH）活性、骨骼肌湿干重比值（wet／dryweightratio,W／D）;电镜观察骨骼肌超微结构变化：Westernblot检测骨骼肌CRT、钙调神经磷酸酶（calcineurin,CaN）的表达。（2）细胞培养实验：原代培养Sprague-Dawley乳鼠骨骼肌细胞,随机分为6组：正常对照组、缺氧／复氧（hypoxia／reoxygenation,H／R）组、缺氧预处理（hypoxic preconditioning,HPC）组、缺氧后处理（hypoxic postconditioning,H-postC）组、CaN抑制剂环孢素A（cyclosporine,CsA）＋H／R组和CsA＋H-postC组。台盼蓝排斥实验、流式细胞仪检测细胞损伤情况：Westernblot检测骨骼肌细胞CRT和CaN的表达。结果显示：（1）在整体动物实验中,I-postC可显著降低血浆LDH活性和组织水肿,骨骼肌超微结构损伤减轻,无细胞核凋亡现象,与IPC组相比无显著差异。I-postC再灌注12h和24hCRT表达分别较I／R12h和24h组高4．39倍和1．02倍（P〈0．05）,CaN表达分别增高1．96倍和0．63倍（尸〈0．05）。相关分析显示CRT表达与CaN表达呈正相关（r-0．865,P〈0．01）。（2）在细胞培养实验中,H-postC可减轻H／R诱导的骨骼肌细胞凋亡,增加细胞存活率,与HPC组相比无显著差异,CsA可抑制H-postC的保护作用;H-postC可上调CRT和CaN的表达,分别较H／R组增加31．8％（P〈0．05）和6．02％,加入CsA后CaN表达降低44．02％（P〈0．05vsH-postC）。上述整体实验和细胞培养实验结果提示,I-postC与IPC保护作用相似,可显著减轻I／R损伤;CRT上调介导的CaN表达增加可能参与了I-postC的保护作用,抑制CaN表达可降低I-postC的保护作用。     

8-Br-cADPR, a TRPM2 ion channel antagonist,inhibits renal ischemia–reperfusion injury

The transient receptor potential melastatin-2 (TRPM2) channel belongs to the transient receptor potential channel superfamily and is a cation channel permeable to Na⁺ and Ca ²⁺. The TRPM2 ion channel is expressed in the kidney and can be activated by various molecules such as hydrogen peroxide, calcium, and cyclic adenosine diphosphate (ADP)-ribose (cADPR) that are produced during acute kidney injury. In this study, we investigated the role of 8-bromo-cyclic ADP-ribose (8-Br-cADPR; a cADPR antagonist) in renal ischemia–reperfusion injury using biochemical and histopathological parameters. CD38, cADPR, tumor necrosis factor-α, interleukin-1β, and myeloperoxidase (inflammatory markers), urea and creatinine, hydrogen peroxide (oxidant), and catalase (antioxidant enzyme) levels that increase with ischemia–reperfusion injury decreased in the groups treated with 8-Br-cADPR. In addition, renin levels were elevated in the groups treated with 8-Br-cADPR. Histopathological examination revealed that 8-Br-cADPR reduced renal damage and the expression of caspase-3 and TRPM2. Our results suggest that the inhibition of TRPM2 ion channel may be a new treatment modality for ischemic acute kidney injury.     

Investigate of AQP gene expression in the liver of mice after ischemia–reperfusion

Ischemia–reperfusion (IR) injury usually occurs during liver transplantation. Aquaporins (AQPs) are transmembrane channels that facilitate water permeability through cell membranes and are essential for the regulation of water homeostasis. Changes in the AQPs expression have been correlated with several inflammatory diseases. Less is known about AQPs expression in hepatic ischemia reperfusion injury. To clarify the roles of AQPs in IR injury, in this current study we examined the gene expression patterns of AQP1, 8 and 9 in the liver after IR injury. Male balb/c mice were exposed to partial (70%) hepatic ischemia for 65 min and then randomized into five groups of reperfusion [0 h (A), 8 h (B), 1 day (C), 3 days (D), and 7 days (E)]. A surgical group was also selected as the sham group. Serum and liver tissue samples were collected for evaluation of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and liver histopathology. Real time PCR was performed to evaluate the AQPs expression. I/R injury resulted in a significant increase in ALT and AST (p?<?0.05) compared to sham mice in each group. The gene expression of AQPs was significantly increased in the IR group compared with the sham group (p?<?0.05). AQP8 and AQP1 after 8 h (group B) showed the highest gene expression in comparison with other groups, but the highest level of AQP9 gene expression was observed after 1 day (group C). Pathologic changes in the liver after reperfusion were confirmed the IR. In the IR group cytoplasmic vacuolization, inflammatory cell infiltration and focal necrosis were detected. In conclusion, our findings indicated that the damage caused by ischemia–reperfusion in the liver can change the expression of AQP genes, which can interfere with hepatocellular homeostasis and their function. Upregulation of AQP1, 8 and 9 could contribute to the development of hepatocellular swelling after hepatic IR injury.     

Evodiamine alleviates kidney ischemia reperfusion injury in rats: A biochemical and histopathological study

Renal ischemia/reperfusion (I/R) injury resulting in acute renal failure, is a major clinical problem due to its high mortality rate. Renal I/R increases the reactive oxygen species, secretion of inflammatory cytokines, chemokines and other factors. This suggests that initiating the apoptosis process in the presence of oxidative stress may play a role in life-threatening conditions, such as ischemia. Ischemia reperfusion-induced renal damage can result in renal failure and death. Although many treatment procedures have been carried out to reduce or destroy renal I/R damage in experimental models, so far, a routine method of treatment has not yet been found. For this reason, the current study was planned to investigate the possible protective effects of evodiamine on tissue damage caused by ischemia-reperfusion in kidney tissue in rats and an experimental renal I/R model was used for this purpose. Four groups were formed in the study: the control, sham control, ischemia reperfusion (I/R), and evodiamine (10 mg/kg) + I/R groups. The effects of evodiamine against kidney I/R injury were investigated. TAS (total oxidant status), TOS (total oxidant status), interleukin-1β (IL-1β), IL-6, IL-10 and tumor necrosis factor-α levels were determined by enzyme-linked immunosorbent assay. The oxidative stress index was calculated from TAS and TOS levels. In addition, the renal ischemia reperfusion injury was examined histopathologically. The IL-10 and TAS levels in the I/R group decreased when compared with the control and Sham groups, while these levels increased in the evodiamine group. Histopathologic examination revealed that caspase 3 and nuclear factor-κB levels decreased in the evodiamine group compared with the I/R group. The application of evodiamine significantly reduced ischemia reperfusion-induced kidney damage due to its antioxidant, anti-inflammatory and antiapoptotic properties.     

Alteration of renal functional, oxidative stress and inflammatory indices following hepatic ischemia-reperfusion

Liver ischemia/reperfusion (IR) injury is a complex phenomenon that may cause local as well as remote organ injuries. Reactive oxygen species (ROS) along with many pro- and anti- inflammatory cytokines are implicated in the development of organ injury. The renal functional, histological, oxidative stress and inflammatory indices were studied during a short and a longer period of liver IR. Rats were subjected to either sham operation or 90 min partial liver ischemia followed by 4 or 24 h of reperfusion. Serum ALT, AST, ALK and LDH levels, BUN and creatinine, renal MDA level, SOD and catalase activities were evaluated as well as serum IL-6 and IL-10 concentrations along with renal histological evaluation. Ninety minutes liver ischemia /4 h reperfusion caused an increase in BUN and renal MDA levels and a decrease in SOD and catalase activities. It also caused an increase in serum IL-6 and IL-10 levels. 24 h liver reperfusion resulted in a reduction in BUN levels and lower oxidative damages demonstrated by a decrease in renal MDA levels and an increase in renal SOD and catalase activities comparing to 4 h reperfusion group. Evaluations indicated improvement in histology such as less cytoplasmic vacuolation and lower tubular debris. Serum inflammatory indices (IL-6 and IL-10 levels) were also reduced. This study showed that liver IR damage causes renal injury including functional, inflammatory and oxidative status changes. The remote kidney damage was then improved by continuing reperfusion from 4 to 24 h.