曲美他嗪对大鼠心肌缺血-再灌注损伤的保护作用

目的探讨曲美他嗪(TMZ)对缺血-再灌注(I-R)后大鼠心肌细胞凋亡的保护作用。方法 SD大鼠随机分为假手术组(A组)I、-R组(B组)、低浓度TMZ(1 ml/100 g)组(C组)和高浓度TMZ(3 ml/100 g)组(D组),每组6只。制备大鼠心肌I-R模型,采用流式细胞仪(FCM)、原位末端标记(TUNEL)技术、免疫组化检测心肌组织细胞凋亡情况,并观察细胞形态变化。结果 B组细胞凋亡指数、TUNEL阳性细胞数、Bcl-2、Bax较A组增高[(0.2416±0.0263)vs.(0.0469±0.0136),(3.213±0.14)vs.(0.44±0.133),(2.057±0.187)vs.(0.47±0.082),(4.257±0.135)vs.(0.52±0.058)(P<0.05)],而C、D组细胞凋亡指数、TUNEL阳性细胞数、Bax明显下降(P<0.05),D组减低更明显。结论 TMZ可抑制心肌I-R损伤中的细胞凋亡。     

Attenuation of glycerol-induced acute renal failure in rats by trimetazidine and deferoxamine

The pathogenesis of glycerol-induced myoglobinuric acute renal failure involves, among other causes, ischaemia, vascular congestion, and reactive oxygen metabolites. The aim of this study was to investigate the roles of ischaemia and iron-induced oxidative stress by employing trimetazidine, an anti-ischemic drug with an additional antioxidant effect, and deferoxamine, an iron chelator, in glycerol-induced acute renal failure in rats. Five groups of rats were employed in this study: group 1 served as control group, group 2 was given 50% glycerol alone (8 ml/kg i.m.), group 3 was given glycerol plus trimetazidine (3 mg/kg), and groups 4 and 5 were given glycerol plus deferoxamine (50 and 100 mg/kg, respectively). Renal injury was assessed by measuring plasma creatinine and blood urea nitrogen levels and creatinine and urea clearances. The oxidative stress was measured on the basis of the renal malondialdehyde and reduced glutathione levels and the activities of catalase, glutathione reductase, and superoxide dismutase. Glycerol treatment resulted in marked renal oxidative stress and deranged renal functions which significantly improved by trimetazidine and deferoxamine treatments. Deferoxamine, by interacting with Fenton reaction chemistry, and trimetazidine, by its anti-ischaemic and antioxidative properties, protected the kidney against the oxidative stress and the resultant renal dysfunction produced by glycerol. Based on these results, this study points towards renal ischaemia and iron as potential mediators and demonstrates the potential beneficial effects of deferoxamine and trimetazidine in glycerol-induced acute renal failure in rats.     

Attenuation of renal ischaemic injury by felodipine

Summary Felodipine is a vasodilating calcium channel blocker of the dihydropyridine type. The effects of felodipine on post-ischaemic renal function were evaluated in rats subjected to bilateral renal artery occlusion for 30 or 60 min.In a first set of experiments the recovery of renal function after 30 or 60 min of renal artery occlusion was followed intermittently for 16 days by endogenous creatinine clearance. Renal function was better preserved in rats given felodipine (45 nmol/kg i.v.) during the occlusion period than in vehicle-treated control rats. The survival rate after 60-min occlusion was 11% in controls but 70% in the felodipine-treated rats. After occlusion for 30 min the survival rate was similar in the two groups, but renal function recovered faster in the felodipine group than in the controls.In a second series, acute renal damage was evaluated by the extent of erythrocytes trapped in the kidney after 30-min reperfusion following 60-min renal artery occlusion. Felodipine administration (45 nmol/kg) during the occlusion reduced renal damage compared with vehicle controls. Kidney weight and systemic haematocrit were also better maintained in the felodipine-treated rats. Furthermore, renal damage was reduced by the t-butyl analogue or felodipine, H 186/86, which is devoid of vasodilatory effects. The results demonstrate that treatment with the vasodilator calcium channel blocker felodipine protects the kidney from ischaemic/reperfusion injuries. The tissue protection is not related to the haemodynamic effects alone, since the haemodynamically inactive dihydropyridine H 186/86 also reduced the extent of renal damage. An additional antiperoxidant or scavanger-like effect inherent in the dihydropyridine molecule is suggested. Send offprint requests to M. Nordlander at the above address     

番茄红素对肾脏缺血再灌注损伤大鼠的保护作用

目的 探究番茄红素(LP)通过抑制硫氧还蛋白相互作用蛋白/NOD样受体热蛋白结构域相关蛋白3(TXNIP∕NLRP3)信号通路保护大鼠肾脏缺血再灌注损伤(IRI).方法 100只大鼠随机分为对照组(n=25)、模型组(n=25)及低剂量实验组(n=25)、高剂量实验组(n=25).模型组及低/高剂量实验组均采用右侧肾切...     

山药对大鼠肾缺血再灌注损伤的保护作用

目的 研究山药灌胃预处理对大鼠肾脏缺血再灌注损伤的保护作用和促进肾脏再生修复的作用.方法 3～4周龄雄性大鼠60只随机分正常对照(A)组(n=6)、假手术对照(B)组(n=6)、缺血再灌注损伤山药灌胃预处理(C)组(n=24)及缺血再灌注损伤无菌生理盐水灌胃对照(D)组(n=24).C、D组在缺血再灌注损伤前灌胃5 d,在损伤后2、12、24、48 h分别采集6只鼠的血并收获肾脏标本.4组标本进行尿素氮、肌酐、丙二醛测定,常规病理切片、细胞凋亡、免疫组化检测增殖细胞抗核抗体(PCNA)、激光共聚焦免疫荧光检测5-溴脱氧尿嘧啶核苷(BrdU)、同源盒基因2(Pax-2).结果 C组尿素氮、肌酐、丙二醛明显低于D组;缺血再灌注损伤2h可测到肾小管细胞凋亡,12 h达高峰;C组凋亡指数明显低于D组;C组PCNA阳性肾小管细胞明显高于D组;C组检测到BrdU、Pax-2双标记阳性细胞;常规病理形态4组有其特有表现.结论 山药灌胃预处理能减轻肾脏缺血再灌注损伤大鼠的多项检测指标,促进受损肾小管的再生修复和重建,有效保护了肾功能.肾脏缺血再灌注损伤后测到的BrdU、Pax-2双标记阳性细胞提示肾组织内的祖细胞参与了肾脏的修复再生.     

The effect of 5-aminosalicylic acid on renal ischemia-reperfusion injury in rats

Objectives:

Ischemia-reperfusion (IR) contributes to the development acute renal failure. Oxygen free radicals are involved in the pathophysiology of IR injury (IRI). This study was designed to investigate the effects of 5-aminosalicylic acid (5-ASA), which is known antioxidant agent, in IR-induced renal injury in rats.

Materials and Methods:

Male Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 24 h of reperfusion. 5-ASA (300 mg/kg, i.p) was administered prior to ischemia. After 24 h reperfusion, urine and blood samples were collected for the determination of creatinine (Cr) and nitric oxide (NO) levels, and renal samples were taken for the histological evaluation.

Results:

Treatment with 5-ASA significantly decreased serum Cr and NO levels, also significantly increased urinary Cr level and decreased histopathological changes induced by IR.

Conclusion:

Treatment with 5-ASA had a beneficial effect on renal IRI. These results may indicate that 5-ASA exerts nephroprotective effects in renal IRI.KEY WORDS: 5-aminosalicylic acid, antioxidant, nitric oxide, renal ischemia-reperfusion     

RETRACTED: Effect of trimetazidine on renal ischemia/reperfusion injury in rats

There is increasing evidence to suggest that toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. This study was designed to investigate the effects of trimetazidine, in I/R induced renal failure in rats. The protective effect of trimetazidine (Tmz) against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Sprague-Dawley rats using histopathological and biochemical parameters. In one set of experiments animals were unilaterally nephrectomized, and subjected to 45 min of left renal pedicle occlusion and in another set both the renal pedicles were occluded for 45 min followed by 24 h of reperfusion. Trimetazidine (3 mg kg(-1), i.p.) was administered 30 min prior to ischemia and repeated 12 h after the first dose. At the end of the reperfusion period, rats were sacrificed. Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, glutathione reductase (GR) catalase (CAT), and superoxide dismutase (SOD) activities were determined in renal tissue. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured for the evaluation of renal function. Ischemic control animals demonstrated severe deterioration of renal function, renal morphology and a significant renal oxidative stress. Pretreatment of animals with trimetazidine markedly attenuated renal dysfunction, morphological alterations, reduced elevated TBARS levels and restored the depleted renal antioxidant enzymes. The findings imply that ROS play a causal role in I/R induced renal injury and trimetazidine exert renoprotective effects probably by the radical scavenging and antioxidant activities.     

Investigation of the renal injury caused by liver ischemia-reperfusion in rats

To explain the mechanism of renal injury caused by liver ischemia-reperfusion, we investigated biochemical and morphological changes in the liver and kidney in rats. After reperfusion following 60 min of liver ischemia, numerous changes were found. The level of serum transaminases and lipid peroxide formation in the liver tissue increased significantly. Electron microscopic studies revealed that most of the hepatocytes had swollen mitochondria and clumping of the nuclear chromatin. The sinusoidal endothelium was disrupted and the sinusoidal lumen was filled with numerous erythrocytes. Blood endotoxin concentration, plasma lipid peroxide levels, and serum -glucuronidase activities were significantly higher than in the control group. Biochemical and morphological renal injury was also observed. Tissue lipid peroxide levels increased in both the kidney and the liver. Microscopic examination revealed damage to the renal tubules, including interstitial edema, dilatation of the lumen, and granular casts derived from necrotic cells in the proximal convoluted tubule. The levels of urinary N-acetyl--d-glucosaminidase (NAG) in the liver ischemia-reperfusion group were also higher than in the control group. These results suggest that the renal injury was caused by an increase in endotoxin, lipid peroxide, and lysosomal enzymes in the blood following the liver injury induced by the ischemia-reperfusion.     

Effect of trimetazidine on the nucleotide profile in rat kidney with ischemia-reperfusion injury.

Ischemia-reperfusion injury is often responsible for delayed graft function after transplantation. Trimetazidine (TMZ) is an antioxidant agent used to protect grafts from ischemia-reperfusion injury. The aim of the study was to examine the effect of TMZ on nucleotide profile in rat kidney with ischemia-reperfusion injury. The study was carried out on Wistar rats divided into two groups: animals treated with TMZ and control group receiving placebo. TMZ 10mg/kg/day was administrated for 30 days. Concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), adenosine (Ado), guanosine triphosphate (GTP), guanosine diphosphate (GDP), guanosine monophosphate (GMP), guanosine (Guo), inosine monophosphate (IMP), inosine (Ino), hypoxanthine (Hyp), xanthine (Xan), uric acid (UA), uridine (Urd), nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) were determined in kidney tissues after ischemia-reperfusion using HPLC. The total adenine nucleotide concentration (TAN) and adenylate energy charge (AEC) were also determined. Moreover the kidneys were evaluated histologically. Tissue concentrations of ATP, ADP, AMP, TAN and AEC were significantly increased in kidneys from rats treated with TMZ in comparison with rats receiving placebo. Concentrations of products of nucleotide degradation: inosine (Ino), guanosine (Guo) and uridine (Urd), as well as oxypurines: Hyp and Xan, were significantly decreased in rats treated with trimetazidine. Moreover, significantly less pronounced acute tubular necrosis was observed in kidneys of rats treated with TMZ. These results suggest that trimetazidine protects against dephosphorylation of nucleotides and ischemic damage.     

Panax ginseng administration in the rat prevents myocardial ischemia-reperfusion damage induced by hyperbaric oxygen: evidence for an antioxidant intervention

The aim of this work was to investigate in the rat the protective effect of an oral administration (one week) of Panax ginseng (PG) extract (10 mg/ml in drinking water; 1.6 g/kg/day) on myocardial post-ischemic damage induced by hyperbaric oxygen (HBO) and on the loss in functionality of the endothelium in aorta ring preparations. The hearts from control rats (no-HBO and no-HBO-PG), and from rats exposed to HBO and to HBO after PG treatment were isolated and subjected to mild ischemia and then reperfused. HBO greatly worsens the post-ischemic damage in controls, as demonstrated by the rise of left ventricular end diastolic pressure (LVEDP) and coronary perfusion pressure (CPP). PG significantly restrained the increase of LVEDP and CPP in respect to HBO-untreated rats, as well as that of CPP induced by injection of angiotensin II during pre-ischemia. In HBO control rats the reduction of the vasorelaxant effect of acetylcholine on norepinephrine precontracted aortic rings, was markedly recovered by PG; a similar trend was observed in aortic rings challenged with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (56% recovery). These results strongly indicate that PG prevents the myocardial ischemia/reperfusion damage and the impairment of endothelial functionality induced by reactive oxygen species arising from HBO exposure, through an antioxidant intervention. The in vitro radical scavenging activity of PG seems to be too weak (0.05-0.5 mg/ml) to explain by itself the cardiac and extra-cardiac protective effects, and this suggests a role also for an indirect antioxidant action of the drug (endothelial nitric oxide synthase stimulation).     

左卡尼汀对脑缺血再灌注损伤的抗氧化作用及其机制研究

目的:观察左卡尼汀对脑缺血再灌注损伤的保护作用,探讨其作用机制。方法:健康雄性Wistar大鼠40只,随机分成4组:假手术组、生理盐水对照组、左卡尼汀100 mg/kg治疗组及左卡尼汀200 mg/kg治疗组,每组10只。采用线栓法制备大脑中动脉缺血再灌注模型,缺血2 h,再灌注24 h,观察左卡尼汀对脑组织丙二醛(MDA)、超氧化物歧化酶(SOD)含量的影响,HE染色观察大鼠脑组织的病理改变。结果:左卡尼汀可明显减少MDA的含量,升高SOD活性,同生理盐水对照组相比,P<0.01。结论:左卡尼汀对脑缺血再灌注损伤有保护作用,与提高脑组织中抗氧化酶活性、抑制氧自由基产生及脂质过氧化反应有关。     

Carvedilol and trimetazidine attenuates ferric nitrilotriacetate-induced oxidative renal injury in rats

Intraperitoneal (i.p.) injection of ferric nitrilotriacetate (Fe-NTA) induces acute proximal tubular necrosis as a consequence of lipid peroxidation and oxidative tissue damage, which eventually leads to high incidence of renal adenocarcinoma in rodents. This study was designed to investigate the effect of carvedilol, an antihypertensive and trimetazidine, an antiischemic, both the drugs with additional antioxidative potentials, on Fe-NTA induced nephrotoxicity in rats. One hour after a single i.p. injection of Fe-NTA (8 mg iron per kg), a marked deterioration of renal architecture and renal function as evidenced by a sharp increase in blood urea nitrogen (BUN) and serum creatinine was observed. Fe-NTA induced a significant renal oxidative stress demonstrated by elevated thiobarbituric acid reacting substances (TBARS) and reduction in activities of renal catalase, superoxide dismutase (SOD) and glutathione reductase (GR). Pretreatment of animals with carvedilol (2 mg/kg, i.p.) as well as with trimetazidine (3 mg/kg, i.p.), 30 min before Fe-NTA administration markedly attenuated renal dysfunction, reduced elevated TBARS, restored the depleted renal antioxidant enzymes and normalised the renal morphological alterations. These results clearly demonstrate the role of oxidative stress and its relation to renal dysfunction, and suggest a protective effect of carvedilol and trimetazidine on Fe-NTA-induced nephrotoxicity in rats.     

Effects of ulinastatin on renal ischemia-reperfusion injury in rats

AIM: To investigate the effect and possible mechanism of ulinastatin on renal ischemia-reperfusion injury in rats. METHODS: Male Sprague-Dawley rats were subjected to 45-min bilateral renal ischemia, treated with intravenously 12 500 U ulinastatin at 30 min prior to ischemia and at the beginning of reperfusion, compared with a nontreated group without ulinastatin and a sham-operation group without bilateral renal ischemia. After 0 h, 2 h, 6 h, 12 h, and 24 h of reperfusion, serum creatinine and blood urea nitrogen were measured for the assessment of renal function, renal sections were used for histologic grading of renal injury, for immunohistochemical localization of Bcl-2 and heat shock protein 70. Renal ultrastructure was observed through a transmission electron microscope. RESULTS: Ulinastatin significantly reduced the increase in blood urea nitrogen and creatinine produced by renal ischemia-reperfusion, suggesting an improvement in renal function. Ulinastatin reduced the histologic evidence of renal     

Attenuation of cerebral ischemia-reperfusion injury by specific activation of Kv7/KCNQ/Mchannels

OBJECTIVE To test any neuroprotective effect of KCNQ channel openers on ischemic injury in mice. METHODS Mouse model of ischemic-reperfusion(I/R) was established by transient middle cerebral artery occlusion(t MCAO). Neurologic deficit scores and infarct volume measurement were assessed. Open field, accelerating rotarod and grip strength were performed for assessment of neurological behaviors. The in vitro model of oxygenglucose deprivation(OGD)-induced injury in mouse primary culture of cortical neurons was used, and cell viability was determined by measurement of release of lactate dehydrogenase(LDH) and using Cell Counting Kit-8(CCK-8) assay after OGD injury. Whole-cel clamp recordings of cortical neuronswere carried out before and after OGD injury. RESULTS The t MCAO caused predictable and consistently sized necrotic brain lesions and behavioral deficits. Injection of KCNQ channel openersretagabine(10 mg·kg-1) or SCR2862(1 mg·kg-1) into tail vein 30 min before surgery significantly decreased neurological scores and brain infarct size in male mice(8-10 weeks)at 24 h after t MCAO. Kv7 activation improved the track length and speed of mice in open field test, and increased the latency to fallon rotarod test. The grip strength of affected side forelimb was also enhanced in mice treated with KCNQ channel openers. Furthermore, neurons incubated with KCNQ channel openers 1 h before OGD exposure showed an increased cell vitality and decreased release of LDH when subjected to OGD injuryfor 20 min.OGD exposure for 5 min caused a significant depolarization of resting membrane potential and action potential threshold in cortical neurons. Electrophysiological recordings revealed that Kv7 opener retigabine can suppress neuronal excitability by reducing the resting membrane potential, decreasing firing frequency and prolonging the action potential latency. CONCLUSION An obvious improvement in the reduction of brain injury and was observed in mouse model of ischemic injury after administration of KCNQ channel openers attenuates brain ischemic injury and also improves functional outcome. Activation of Kv7 channel function also protects cortical neurons against OGD-induced injury. Mechanistical y, KCNQ channel openers suppress neuronal hyperexcitability after OGD and brain ischemia injury.     

四氢生物蝶呤对大鼠肾缺血再灌注损伤的作用

目的：探讨四氢生物蝶呤(BH4)对肾缺血再灌注损伤(IR)模型的作用及其作用机制。方法：复制大鼠肾缺血再灌注模型，手术前1h喂饲BH4，动态检测其对肾组织NO含量、cNOS和iNOS活性的影响，并通过肾功能、MPO、MDA的变化来评价BH4对肾IR模型的作用。结果：BH4能够升高再灌注早期cNOS活性，增加内皮源性NO含量，减轻炎症反应，减弱再灌注后期对iNOS的诱导作用。结论：BH4可改善再灌注初期cNOS活性，保护肾功能。     

Assessment of renal injury in vivo

The ICH S7A (Safety Pharmacology for Human Pharmaceuticals) guidelines specify that potential adverse pharmacologic effects of a test substance on renal function should be evaluated in supplemental studies when there is a cause for concern (ICH, 2001). For the most part, this can easily be accomplished by examination of the appropriate analytes in urine and blood collected as part of the routine preclinical safety studies. This review will serve as an overview of the selection, interpretation and limitations of standard clinical pathology methods (serum chemistry and urinalysis) for assessment of renal function in such studies, as well as provide some information on emerging biomarkers of renal function.     

肾缺血再灌注损伤对大鼠肾脏CD44表达的影响

目的 观察大鼠肾缺血再灌注损伤(RIRI)对肾脏CD44表达的影响.方法 健康Wistar大鼠48只,体重300～350g,随机分为4组(n=12):假手术组(sham组)只分离肾动脉不夹闭;肾缺血60min再灌注1h组(I/R1h组),双肾缺血60min再灌注1h;肾缺血60min再灌注4h组(I/R4h组),双肾缺血60min再灌注4h;肾缺血60min再灌注24h组(I/R24h组),双肾缺血60min再灌注24h.实验结束处死大鼠,抽血检测血清CD44含量,光镜观察肾脏组织形态学改变,免疫组化检测肾脏CD44分子的表达.结果 光镜观察sham组肾组织肾小球较多,肾小管结构完整.I/R各组肾小球毛细血管扩张、淤血,部分肾小球纤维化,体积缩小,大量肾小管细胞水肿、变性,宫腔缩小,部分肾小管腔闭合.其中以I/R4h组形态学改变最明显.I/R各组血清CD44含量分别为(0.88±0.03)ng/ml、(10.22～3.01)ng/ml、(40.12±6.59)ng/ml、(8.12±1.59)ng/ml,肾组织表达分别为0.41±0.024、14.35±5.262、36.357±8.774、10.317±3.726.各组表达均较sham组升高,但是I/R4h组高于其他组(P<0.05).结论 大鼠肾脏缺血再灌注后CD44表达增加,再灌注4h达到峰值,24h开始回落.     

The effect of naringin, a bioflavonoid on ischemia-reperfusion induced renal injury in rats.

There is increasing evidence to suggest that toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. This study was designed to investigate the effects of naringin (Ng), a bioflavonoid in I/R induced renal failure in rats. The protective effect of naringin against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Sprague-Dawley rats using histopathological and biochemical parameters. In one set of experiments animals were unilaterally nephrectomized, and subjected to 45 min of left renal pedicle occlusion and in another set both the renal pedicles were occluded for 45 min followed by 24h of reperfusion. Naringin (400 mg kg(-1), p.o.) was administered 60 min prior to ischemia. At the end of the reperfusion period, rats were sacrificed. Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, catalase (CAT), and superoxide dismutase (SOD) activities were determined in renal tissue. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured for the evaluation of renal function. Ischemic control animals demonstrated severe deterioration of renal function, renal morphology and a significant renal oxidative stress. Pretreatment of animals with naringin markedly attenuated renal dysfunction, morphological alterations, reduced elevated TBARS levels and restored the depleted renal antioxidant enzymes. The findings imply that ROS play a causal role in I/R induced renal injury and naringin exert renoprotective effects probably by the radical scavenging and antioxidant activities.     

乌司他丁对肾脏缺血-再灌注损伤的保护作用

目的探讨乌司他丁对肾脏缺血-再灌注损伤的保护作用.方法取30只雄性新西兰家兔,随机分成三组:对照组(C组)、抑肽酶组(A组)和乌司他丁组(U组),建立兔在体肾脏缺血-再灌注损伤模型.观察三组再灌注后4、24、48h三个时点血尿素氮(BUN)、血肌酐(Cr)和尿N-乙酰-βD-氨基葡萄糖苷酶(NAG)的变化.结果再灌注24、48h,U组BUN值、Cr值比C组和A组低(P＜0.05).再灌注4h,U组NAG值最低,A组其次,C组最高(P＜0.05);再灌注48h,U组和A组NAG值比C组低(P＜0.05),但U组与A组之间无明显差异性.结论乌司他丁能减轻肾脏缺血-再灌注损伤.