Low arginine plasma levels do not aggravate renal blood flow after experimental renal ischaemia/reperfusion.

BACKGROUND: Ischaemic renal dysfunction is present in many clinical settings, including cardiovascular surgery. Renal hypoperfusion seems to be the most important pathophysiologic mechanism. Arginine plasma levels are rate limiting for NO synthesis, and low arginine plasma levels are seen after major vascular surgery. OBJECTIVE: to establish the effects of low arginine plasma levels on renal blood flow after renal ischaemia/reperfusion. DESIGN: Wistar rats were used in this unilateral renal ischaemia/reperfusion model. After 70 min of ischaemia, the kidney was reperfused for 150 min. Arginase infusion was used to lower arginine plasma levels. Blood flow measurement was performed at the end of the experiment using radiolabelled microspheres. Additional experiments were performed for histopathology. RESULTS: Arginase efficiently decreased arginine plasma levels to about 50% of normal. There was a lower blood flow in the ischaemic kidney than the contralateral (non-ischaemic) kidney. Lowering arginine plasma levels did not reduce renal blood flow in the ischaemic kidney. Renal histopathology was not influenced by lowered arginine plasma levels. CONCLUSIONS: Lowering arginine plasma levels did not affect blood flow or histology following renal ischaemia and reperfusion.     

STF-083010对肾脏缺血-再灌注损伤的保护作用

目的 观察STF083010对急性肾缺血-再灌注损伤的作用,探讨其损伤保护作用的机制.方法 选择健康雄性SD大鼠30只,随机分为假手术组(打开腹腔)、I-R组(建立大鼠肾I-R损伤模型)与STF083010组.分别在缺血-再灌注24h后处死大鼠,取血液和肾组织.全自动生化仪检测各组血清尿素氮(BUN)及肌酐(Scr)水平.PAS染色观察大鼠肾组织病理变化,免疫组化检测肾脏组织中XBP1、GRP78蛋白的表达.Quantitative real-time PCR(QPCR)测定大鼠肾组织标本中XBP1、GRP78 mRNA水平.结果 I-R组肌酐、尿素氮水平与假手术组相比差异均有统计学意义(P＜0.05).STF-083010组与I-R组相比,差异亦有统计学意义(P＜0.05).PAS病理图片可见STF-083010组肾小管损伤较I-R组明显减轻(P＜0.05);免疫组化检测显示STF-083010组XBP1的表达较I-R组明显降低(P＜0.05),STF-083010组GRP78蛋白的表达较I/R组明显升高;QPCR结果显示STF-083010组XBP1 mRNA水平较I-R组明显降低(P＜0.05),STF-083010组GRP78 mRNA较I-R组明显升高(P＜0.05).结论 STF-083010可以对大鼠肾脏缺血-再灌注损伤性保护作用.     

Regulation of ROMK and channel-inducing factor (CHIF) in acute renal failure due to ischemic reperfusion injury

BACKGROUND: Acute renal failure caused by ischemia followed by reperfusion is often associated with severe hyperkalemia. The present study was undertaken to characterize the effects of renal ischemia and reperfusion on plasma potassium (K) and on the gene expression of channel-inducing factor (CHIF), a putative K channel regulator, and of ROMK, the distal nephron secretory K channel. METHODS: The following groups of rats were studied: (1) sham operated (sham); (2) after one hour of ischemia by bilateral renal artery clamping (I), and after one hour of ischemia; (3) one hour of reperfusion (I-R 1 h); (4) 24 hours of reperfusion (I-R 24 h); (5) 48 hours of reperfusion (I-R 48 h); and (6) 72 hours reperfusion (I-R 72 h). The expression of CHIF and ROMK was examined by Northern blot hybridization in renal cortex, medulla, and papilla and in the colon. The abundance of ROMK protein was determined in the renal cortex and medulla by immunoblotting. RESULTS: Maximal plasma creatinine and potassium levels after ischemia and reperfusion were 470 +/- 16 micromol/L, P < 0.0001 versus sham, and 9.65 +/- 0.33 mmol/L, P < 0.0001 versus sham, respectively. The expression of CHIF was significantly down-regulated in the medulla and papilla, with a maximal decrease of 80% at 48 to 72 hours. In contrast, a most significant increase in CHIF mRNA expression (250% of baseline) was noted in the colon after 24 to 48 hours of reperfusion. ROMK expression was reduced in the cortex and was completely abolished in the medulla at 48 to 72 hours of reperfusion. Ischemia and reperfusion injury significantly decreased ROMK protein abundance to 10% of control in the medullary fractions. CONCLUSIONS: These results suggest that down-regulation of renal CHIF and ROMK may contribute at least partly to the hyperkalemia of acute renal failure after ischemia and reperfusion, while CHIF up-regulation in the colon may act as a compensatory mechanism of maintaining K balance via increased K secretion.     

Effect of Dexmedetomidine on Ischemia-Reperfusion Injury in Rat Kidney: A Histopathologic Study

Ischemia-reperfusion (I-R) injury remains the leading cause of acute renal failure. The purpose of this experimental study was to determine the role of dexmedetomidine on histologic alterations induced by renal I-R in rats. In the present study, thirty male Sprague-Dawley rats weighing 200–220 g were randomly assigned into three groups: the sham-control group (group 1, n?=?10), the R/untreated group (group 2, n?=?10), and the I-R/dexmedetomidine-treated group (group 3, n?=?10). For group one, we performed a sham operation. The abdomen was dissected, the right kidney was harvested, and then the left renal pedicle exposed. Renal clamping was not applied. For group 2, rats underwent left renal ischemia for 60 minutes followed by reperfusion for 45 minutes. For group 3, the same surgical procedure as in group 2 was performed, and dexmedetomidine (100 μg/kg, intraperitoneal) was administrated at the starting time of reperfusion. The rats were sacrificed after reperfusion, and the kidney tissue was harvested. The histopathological score in the kidney of the I-R/dexmedetomidine-treated group rats was significantly lower than that of I-R/untreated group rats. This score in I-R/untreated group rats was higher than the other two groups, which was statistically significant. In the I-R/untreated group rats, kidneys of untreated ischemia rats showed tubular cell swelling, cellular vacuolization, pyknotic nuclei, medullary congestion, and moderate to severe necrosis. Treatment with dexmedetomidine shows normal glomeruli and slight edema of the tubular cells. These findings provide the first evidence that dexmedetomidine can reduce the renal injury caused by I-R of the kidney, and may be useful in enhancing the tolerance of the kidney against renal injury.     

大鼠小肠缺血再灌注后肾脏损伤

通过对２０只大鼠小肠缺血再灌注模型和肾组织中脂质过氧化物的测定,并结合病理改变,以探讨小肠缺血再灌注后肾损伤的病理机制。结果表明：大鼠小肠缺血再灌注后,血脂质过氧化物明显升高,同时关浆内脂质过氧物明显高于对照组。提示小肠缺血再灌注后肾组织细胞确有明显损伤,其中氧自由基对肾组织的破坏可能是肾脏病理生理改变的主要因素。     

肢体缺血后处理和肾脏缺血后处理对大鼠肾脏缺血-再灌注损伤的影响

目的 探讨肢体缺血后处理和肾脏缺血后处理对大鼠肾脏缺血-再灌注(I-R)损伤的影响.方法 24只大鼠随机均分为假手术组(S组)、缺血-再灌注组(I-R组)、左下肢缺血后处理组(LIP组)及肾脏缺血后处理组(RIP组).S组仅对左肾动脉进行游离;I-R组:夹闭左肾动脉45 min后松开,左肾再灌注6 h;LIP组在左肾复灌前6 min时左股动脉夹闭5 min;RIP组在左肾缺血45min后灌注10 s,停灌10 s,反复6次;检测复灌6 h时血清肌酐(Cr)、血尿素氮(BUN);光镜下观察肾组织病理改变,TUNEL法检测肾组织中凋亡细胞并计算凋亡指数(AI);免疫组化法检测肾组织Fas、Caspase-3表达;电镜下观察肾单位超微结构改变.结果 与S组比较,其他三组大鼠BUN、Cr浓度升高(P<0.01)、肾组织病理改变明显、肾组织Fas、Caspase-3阳性指数和AI增加(P<0.01).与I-R组比较,LIP、RIP组大鼠BUN、Cr浓度降低(P<0.01),肾组织Fas、Caspase-3阳性指数和AI降低(P<0.01).RIP组AI明显低于LIP组(P<0.05).结论 在肾脏I-R损伤的病理过程中,肾小管上皮细胞凋亡可以由胞膜上的Fas被激活而最终导致靶细胞凋亡;两种后处理都可以抑制肾小管上皮细胞凋亡,减轻I-R损伤.     

Inhibition of nitric oxide synthase reduces renal ischemia/reperfusion injury

BACKGROUND: The role of nitric oxide (NO) production because of inducible nitric oxide synthase (iNOS) in the pathogenesis of renal ischemia/reperfusion (I/R) injury is unclear. In this study the roles of both iNOS and NO were characterized in a rat model of renal I/R injury. In addition, the effect of iNOS inhibition on renal function was evaluated. METHODS: Sprague-Dawley rats underwent 45 min of left renal ischemia and contralateral nephrectomy followed by various periods of reperfusion and renal function analysis [plasma creatinine, fractional excretion of sodium (FENa), creatinine clearance (CrCl), and measurement of plasma and urine NO levels]. In addition, the effect of treatment with 1400W, a highly selective iNOS inhibitor, was evaluated. RESULTS: Renal dysfunction peaked at 48 h after reperfusion and immunohistochemistry studies revealed iNOS expression in the vasculature (3 h) and renal tubules (48 h) after reperfusion. Renal function improved significantly in treated animals compared to controls [creatinine of 1.1 v. 1.9 mg/dl (P < 0.05) and CrCl of 0.54 v. 0.31 ml/min (P < 0.05), respectively]. In addition, FENa was decreased by 50%, plasma NO levels were significantly lower (32.7 v. 45.7 micromol/L, P < 0.01), and deposition of nitrotyosine in the tubules of treated rats was less than in control animals. CONCLUSIONS: These data support the hypothesis that iNOS and NO are involved in the pathogenesis of renal I/R injury and suggests that use of iNOS inhibitors may be a valuable therapeutic strategy clinical situations where renal I/R may be prevalent.     

Carvedilol protects tubular epithelial cells from ischemia–reperfusion injury by inhibiting oxidative stress

Objectives: Renal ischemia–reperfusion injury (IRI), leading to acute kidney injury, is a frequent complication with renal transplantation and it is associated with graft function. Its pathogenesis involves ischemia, vascular congestion and reactive oxygen metabolites. Carvedilol is an antihypertensive drug with potent anti‐oxidant properties. In this study we investigated the protective effects of carvedilol in a rat renal IRI model. Methods: Twenty‐four rats were randomized into sham, untreated control and carvedilol (2 mg/kg 30 min before surgery and 12 hr after reperfusion) treatment groups and were subjected to 60 min of left renal ischemia followed by reperfusion at 24, 48, 96 and 168 hr. Results: Treatment with carvedilol significantly decreased plasma creatinine levels after IRI (up to 168 hr) compared to controls (P < 0.001), suggesting an improvement in renal function. Histopathological analysis revealed decreased IRI‐induced damage in kidneys from carvedilol‐treated rats. A significant increase in the expression levels of Cu/Zn superoxide dismutase and reduction of 8‐hydroxydeoxyguanosine and apoptosis levels (P < 0.005) suggested a protective effect after treatment with carvedilol. Conclusions: Our findings suggest that carvedilol ameliorates IRI resulting in improved renal function.     

Hypothyroidism protects against free radical damage in ischemic acute renal failure

The effect of hypothyroidism on ischemic acute renal failure was studied in rats. Ten days after thyroidectomy with parathyroid reimplantation, rats underwent right uninephrectomy followed by occlusion of the left renal artery for 60 min. Plasma creatinine was lower in thyroidectomized than control rats 24 hr after ischemia; 1.3 +/- 0.5 vs. 3.2 +/- 0.6 mg%; P less than 0.05. Twenty-four hours after ischemia, inulin clearance was higher in thyroidectomized than control animals (0.40 +/- 0.06 vs. 0.17 +/- 0.03 mliter/min; P less than 0.01), despite an initially lower inulin clearance in thyroidectomized animals (0.81 vs. 1.1 +/- 0.07 mliter/min; P less than 0.05). Administration of the antithyroid drug prophylthiouracil for 14 days also resulted in lower plasma creatinine after ischemia. Kidneys from thyroidectomized animals showed less histologic damage 24 hr after ischemia. Renal cortical content of the lipid peroxidation product malondialdehyde was increased less in thyroidectomy than control kidneys after 60 min ischemia plus 15 min reflow (0.08 +/- 0.02 vs. 0.42 +/- 0.1 nmole/mg protein; P less than 0.005). Renal cortical glutathione content was higher in thyroidectomized animals by approximately 36%, 650 +/- 46 vs. 479 +/- 32 nmole/mg protein (P less than 0.02). In normal rats, glutathione infusion also increased renal cortical glutathione content and resulted in lower plasma creatinine 24 hr after renal artery ischemia. Therefore, hypothyroidism resulted in functional and histologic protection against injury after ischemia. Post-ischemic renal lipid peroxidation was reduced in thyroidectomized animals, perhaps the result of increased scavenging of reactive oxygen species (oxygen free radicals and H2O2) by glutathione.     

Nitric oxide regulates expression of sonic hedgehog and hypoxia-inducible factor-1alpha in an experimental model of kidney ischemia-reperfusion

This study was designed to determine the effect of L-arginine on hypoxia inducible factor alpha (HIF-1 alpha) and Sonic hedgehog (Shh) levels considered to be involved in the development of ischemia/reperfusion (I/R) injury. Unilaterally nephrectomized Sprague-Dawley rats were subjected to 60 minutes of left renal ischemia followed by 45 minutes of reperfusion. Group 1 were sham-operated animals; group 2, I-R/Untreated animals; and group 3, I-R/L-Arg-treated animals. Serum creatinine, blood urea nitrogen (BUN), and kidney malondialdehyde (MDA) levels were determined as well as examining the kidneys histologically. The treatment of rats with L-Arg produced a significant reduction in the levels of BUN, creatinine, MDA, and histopathological score compared to renal I/R groups. The Shh expression in the tubulus epithelia were intensely increased in the I-R/L-Arg group when compared to that of the Sham-control and the I-R/untreated groups. Additionally, the HIF-1alpha expression in the tubulus epithelia and the interstitial spaces were intensely increased in the I-R/L-Arg group. These findings suggest that NO reduces the renal dysfunction associated with I/R of the kidney and may act as a trigger to induce Shh and HIF-1 activity.     

Nitric Oxide Regulates Expression of Sonic Hedgehog and Hypoxia-Inducible Factor-1α in an Experimental Model of Kidney Ischemia-Reperfusion

This study was designed to determine the effect of L-arginine on hypoxia inducible factor alpha (HIF-1 α) and Sonic hedgehog (Shh) levels considered to be involved in the development of ischemia/reperfusion (I/R) injury. Unilaterally nephrectomized Sprague-Dawley rats were subjected to 60 minutes of left renal ischemia followed by 45 minutes of reperfusion. Group 1 were sham-operated animals; group 2, I-R/Untreated animals; and group 3, I-R/L-Arg-treated animals. Serum creatinine, blood urea nitrogen (BUN), and kidney malondialdehyde (MDA) levels were determined as well as examining the kidneys histologically. The treatment of rats with L-Arg produced a significant reduction in the levels of BUN, creatinine, MDA, and histopathological score compared to renal I/R groups. The Shh expression in the tubulus epithelia were intensely increased in the I-R/L-Arg group when compared to that of the Sham-control and the I-R/untreated groups. Additionally, the HIF-1α expression in the tubulus epithelia and the interstitial spaces were intensely increased in the I-R/L-Arg group. These findings suggest that NO reduces the renal dysfunction associated with I/R of the kidney and may act as a trigger to induce Shh and HIF-1 activity.     

Renal work, glutathione and susceptibility to free radical-mediated postischemic injury

Studies were performed to determine whether renal glutathione (GSH) is an important free-radical scavenger following ischemia and reperfusion, whether alterations in renal transport work affect renal GSH levels, and whether a decrease in renal work decreases susceptibility to postischemic renal injury via the first two effects. Following administration of either intravenous GSH to increase renal GSH or intraperitoneal diethylmaleate to decrease renal GSH, Sprague-Dawley rats underwent 60 minutes of renal ischemia. In animals with high renal GSH following GSH infusion, GFR 24 hours after ischemia was 0.43 +/- 0.08 ml/min compared to 0.15 +/- 0.02 ml/min in saline-infused control animals (P less than 0.01). When renal GSH was decreased by the administration of diethylmaleate postischemic renal dysfunction was accentuated. Twenty-four hours after ischemia GFR was 0.05 +/- 0.02 ml/min in diethylmaleate-treated animals and 0.28 +/- 0.06 ml/min in control animals (P less than 0.005). To test whether a decrease in renal transport work alters renal GSH the filtered load of sodium was reduced by producing unilateral renal artery stenosis. Alternatively, renal work was lessened when sodium reabsorption was interfered with by the infusion of a combination of natriuretic agents. Renal artery stenosis produced a 37% decrease in GFR. Renal GSH was 0.435 +/- 0.089 nmol/mg protein in intact kidneys and 0.804 +/- 0.239 nmol/mg protein in stenotic kidneys (P less than 0.05). The infusion of natriuretic agents produced no change in GFR or renal plasma flow but resulted in a striking elevation in renal GSH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reduction of renal ischemia reperfusion injury by hydrogen sulfide preconditioning through inhibiting oxidative stress

Objective To investigate the possible role of oxidative stress in the protection of hydrogen sulfide during renal ischemia reperfusion. Methods Male Wistar rats were randomly divided into 3 groups: sham operation (Sham) group, renal ischemia reperfusion (IR) group subject to occlusion of left renal pedicle for 45 min then reperfusion for 24 h, and sodium hydrosulfide (NaHS) preconditioning group with continuous infusion of NaHS (450 nmol/min) by left renal artery for 10 min before ischemia reperfusion. Renal injuries were evaluated by PAS staining. The protein levels of NADPH oxidase (NOX) 4, NOX2 were analyzed by Western blotting. The reactive oxygen species (ROS) level of renal tissue was determined by dihydroethidium (DHE) staining assay. Renal superoxide dismutase (SOD), malonic dialdehyde (MDA) and Scr, BUN were evaluated by chromatometry assay. Cell apoptosis were evaluated by TdT-mediated dUTP nick end labeling (TUNEL) staining. Results Compared with Sham group, in IR group the renal NOX4 and NOX2 protein expressions, the existence of acute tubular necrosis and ROS expression were up-regulated (all P＜0.01); MDA, Scr, and BUN were increased and SOD was decreased significantly in IR-treated kidney (all P＜0.01); Moreover, more apoptotic cells presented in the risk zone of IR-treated kindey (P＜0.01). The effects induced by IR were inhibited by NaHS. Compared to that in IR group, NaHS precondition reversed IR-induced damages of renal function and renal tissue, increased SOD activity and decreased MDA expression (all P＜0.05), as well as reduced the expression of NOX4, NOX2 and ROS (all P＜0.05). Moreover, NaHS precondition reduced apoptosis after IR (P＜0.05). Conclusions NaHS alleviates renal ischemia reperfusion injury through inhibiting oxidative stress. Hydrogen sulfide can decrease ROS by inhibiting the activation of NOX, further inhibit the activation of NOD-like receptor, and alleviate kidney damage.     

内皮素和降钙素基因相关肽在急性肾缺血再灌注损伤中的作用

为研究大鼠急性肾缺血再灌注损伤血液和肾组织中内皮素（ＥＴ）和降钙素基因相关肽（ＣＧＲＰ）的动态变化规律，放射免疫法检测急性肾缺血再灌注损伤大鼠血浆和肾皮质、髓质ＥＴ和ＣＧＲＰ水平变化，结果肾组织ＥＴ水平于再灌注３ｈ达到高峰，２４ｈ仍维持较高水平，肾组织ＣＧＲＰ水平再灌注２４ｈ达到高峰，血浆ＥＴ和ＣＧＲＰ于再灌注损伤后虽升高，但无显著性差异，认为肾组织ＥＴ和ＣＧＲＰ升高在急性肾缺血再灌注损伤和修复中     

Hydrogen sulfide reduce renal ischemia/reperfusion injury by NOD-like receptor pathway

Objective To investigate whether the nod-like receptor (NLR) pathway is involved in protection of hydrogen sulfide (H2S) preconditioning during renal ischemia reperfusion. Methods Male Wistar rats were randomly divided into 3 groups: sham operation (Sham) group, renal ischemia/reperfusion (I/R) group subjected to occlusion of left renal pedicle for 45 min then reperfusion for 24 hours, and sodium hydrosulfide (NaHS) preconditioning group with continuous infusion of NaHS (300 nmol/min) by left renal artery for 15 min before I/R treatment. Renal injuries were evaluated by HE staining. The protein levels of NOD1, NOD2, nuclear NF-κB P65 and caspase-1 were analyzed by Western blot assay. The protein level of MCP-1 and IL-1β expressions was determined by immunohistochemical staining assay. Cell apoptosis were evaluated by Tunel staining assay. Results In I/R group, the renal NOD1 and NOD2 protein expressions were upregulated. Moreover, the nuclear NF-κB P65 expression was also elevated with an increase in its target genes-MCP-1 and IL-1β (All P＜0.01). HE staining revealed the existence of acute tubular necrosis in I/R kidney. TUNEL staining revealed more apoptotic cells in risk zone with the activation of caspase-1 of I/R-treated kidney(P＜0.01). NaHS preconditioning reversed I/R-induced increase in the expression of NOD1 and NOD2(P＜0.05). NaHS preconditioning also reduced I/R-induced activation of NF-κB P65 (P＜0.05) and upregulation of MCP-1 and IL-1β (P＜0.01). Moreover, NaHS preconditioning attenuated inflammation, repressed caspase-1 activation and reduced apoptotic cells after I/R. Conclusion Hydrogen sulfide preconditioning can alleviate renal ischemia/reperfusion injury by Nod-like receptor dependent on inflammatory pathway.     

丹皮酚磺酸钠在动物肾缺血再灌注损伤中的作用

目的：了解丹皮酚磺的钠对肾缺血再灌注损伤模型肾组织病理改变及血浆丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性的影响。方法：将雄性新西兰大白兔右肾切除,阻断左肾动脉,制成肾缺血再灌注模型。按100mg/kg在不同时间应用丹皮酚磺酸钠进行干预治疗,比较不同时间血浆MDA含量和SOD活性变化以及术后48h肾组织病理变化。结果：应用丹皮酚磺酸钠治疗的大白兔。缺血再灌注60min时血浆MDA含量低于对照组,SOD活性高于对照组,肾脏病理改变减轻。结论：丹皮酚磺酸钠可以降低血浆MDA含量,增加SOD活性,对肾缺血再灌注损伤有保护作用。     

Ex vivo carbon monoxide prevents cytochrome P450 degradation and ischemia/reperfusion injury of kidney grafts

Renal ischemia/reperfusion injury is a major complication of kidney transplantation. We tested if ex vivo delivery of carbon monoxide (CO) to the kidney would ameliorate the renal injury of cold storage that can complicate renal transplantation. Orthotopic syngeneic kidney transplantation was performed in Lewis rats following 24 h of cold preservation in University of Wisconsin solution equilibrated without or with CO (soluble CO levels about 40 microM). Ischemia/reperfusion injury in control grafts resulted in an early upregulation of inflammatory mediator mRNAs and progressive deterioration of graft function. In contrast, the grafts preserved with CO had significantly less oxidative injury and this was associated with improved recipient survival compared to the control group. Renal injury in the control group showed considerable degradation of cytochrome P450 heme proteins, active heme metabolism and increased detrimental intracellular free heme levels. Kidney grafts preserved in CO-equilibrated solution maintained their cytochrome P450 protein levels, had normal intracellular heme levels and had less lipid peroxidation. Our results show that CO-mediated suppression of injurious heme-derived redox reactions offers protection of kidney grafts from cold ischemia/reperfusion injury.     

Carbon monoxide protects against ischemia-reperfusion injury in an experimental model of controlled nonheartbeating donor kidney

BACKGROUND: CO-releasing molecule-3 (CORM-3) is a transitional metal carbonyl that liberates carbon monoxide under appropriate conditions. Carbon monoxide exerts effects on intracellular apoptotic and inflammatory pathways, which suggest a role in reducing the effects of renal ischemia/reperfusion (I/R) injury. This study investigated the effects of CORM-3 administered at the time of reperfusion in a model of controlled nonheartbeating donor kidneys. METHODS: Porcine kidneys (n=4) were subjected to 10 min warm ischemia and 18 hr cold storage (CS) and then treated as follows: CORM-3 (50, 100, 200, and 400 microM doses), iCORM-3 (inactive carbon monoxide-releasing molecule, 50 microM), and control (no further intervention). Renal hemodynamics and function were then measured during 3-hr reperfusion with autologous blood using an isolated organ-perfusion system. RESULTS: CORM-3 at a concentration of 50 microM improved renal blood flow (RBF) compared with the iCORM and control groups (area under the curve 774+/-19 vs. 448+/-88 vs. 325+/-70, respectively, P=0.002). CO-releasing molecule-3 at a concentration of 50 microM also improved renal function during reperfusion with a greater area under the curve for creatinine clearance (CORM-3: 14+/-6 vs. iCORM: 3.3+/-0.1 vs. control: 2.2+/-2 mL/min, P=0.006) and higher urine output (CORM-3: 793+/-212 vs. iCORM: 368+/-72 vs. control: 302+/-211 mL, P=0.01). CO-releasing molecule-3 at a concentration of 100 microM exerted similar effects. Treatment with CORM-3 at higher doses (200 and 400 microM) led to poor renal hemodynamics and function after reperfusion. CONCLUSION: Low-dose CORM-3 significantly ameliorates the effects of ischemia/reperfusion in a porcine model of controlled nonheartbeating donor kidney transplantation.     

丙泊酚对大鼠急性肾缺血再灌注损伤的影响

目的 探讨丙泊酚预处理对急性肾缺血再灌注损伤(acute renal ischemia reperfusion injury ,ARIRI)的保护作用及其机制.方法 采用完全随机研究设计(randomized controlled trial,RCT),健康近交系清洁级的雄性SD大鼠63只,随机分为3组:假手术组(A组)、缺血再灌注组(B组)、丙泊酚预处理组(C组),每组21只SD大鼠.采用切除右侧肾,用无损伤微动脉夹夹闭左侧肾蒂60分钟后解除阻断,建立大鼠急性肾缺血再灌注损伤模型.用24号套管针股静脉穿刺置管,实验过程中各组使用微量注射泵注入不同注射液.分别于手术前15分钟、再灌注后2小时、24小时留取血和肾组织标本同时处死大鼠,检测血清尿素氮(BUN)、肌酐(Cr)、超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)及观察这三个时点肾组织的病理学改变.结果 丙泊酚预处理组各个时点的肾组织病理学变化均轻于缺血再灌注组.缺血再灌注组中血清BUN、Cr、MDA和TNF-α水平增加均高于丙泊酚预处理组(p＜0.05),丙泊酚预处理组血清SOD、IL-6水平均高于缺血再灌注组(p＜0.05).结论 丙泊酚预处理组血清BUN、Cr、MDA、TNF-α、SOD、IL-6水平与缺血再灌注组均有统计学差异.结果 表明丙泊酚能减少氧自由基释放,抑制和减少炎症反应,在急性肾缺血再灌注损伤能起到保护肾脏的作用.     

Attenuation of renal ischemia/reperfusion injury by a triple drug combination therapy

BACKGROUND: Renal ischemia is of great clinical interest because of its role in renal failure and renal graft rejection. The purpose of this study was to investigate the therapeutic effects of a combination therapy of: n-acetyl cysteine (NAC), a potent antioxidant, sodium nitroprusside (SNP), a nitric oxide donor and phosphormidon (P), an endothelin-1 converting enzyme inhibitor, on tissue protection against renal ischemia/reperfusion injury in the canine model. METHODS: In this study, 15-20 kg male dogs were subjected to 90 minutes of warm unilateral renal ischemia after removal of one kidney and then divided into control, ischemia alone and treatment groups. Blood samples were collected from these dogs for measurement of kidney function tests and the kidneys were harvested at different time intervals for morphological evaluation, immunostaining and Tunnel Assay. RESULTS: Kidney function tests (serum creatinine and blood urea nitrogen [BUN]) showed a significant difference between untreated and treated groups. ** P <0.01, * P< 0.0001 for treated versus untreated. The protective effect of the combination therapy is also supported by light microscopic studies, immunostaining of renal tissue sections for pro-inflammatory cytokines (TNF-alpha and IFN-gamma), iNOS, and apoptosis by TUNEL assay. CONCLUSIONS: Our results suggest that pre-administration of a combination of NAC, SNP, and P attenuates renal ischemia/reperfusion injury. This has potential application in preservation of donor kidney for transplantation by protecting cells against free radical damage.