内皮素在急性肾缺血再灌注损伤中作用的实验研究

内皮素在急性肾缺血再灌注损伤中作用的实验研究涂响安余明年谢佛龙赵志毅冯家骅何炳辉彭轼平用放射免疫方法（ＲＩＡ）检测大鼠左肾动脉夹闭６０分钟致急性肾缺血再灌注损伤（ＡＲＲＩ）模型其血浆和肾组织内皮素（ＥＴ）水平变化，以探讨ＥＴ在急性肾缺血再灌注损伤中的...     

黄芪对肾缺血再灌注损伤的保护作用

目的 探讨黄芪注射液对肾脏缺血再灌注损伤的影响。方法 观察黄芪注射液对肾缺血再灌注损伤大鼠血浆超氧化物歧化酶（ＳＯＤ）,脂质过氧化产物丙二醇（ＭＤＡ）,内以素－１（ＥＴ－１）,一氧化氮（ＮＯ）变化及肾组织病理改变。结果 黄芪治疗组血浆ＥＴ０－１,ＭＤＡ水平较缺血再灌注组显著下降,ＳＯＤ显著升高,且病理改变较轻。结论 黄芪对肾脏缺血再灌注损伤具有保护作用。．     

体外循环与内皮素和降钙素基因相关肽的临床与实验研究

本文对离体大鼠心脏灌流及体外循环心内直视手术期间的内皮素和降钙素基因相关肽水平进行了动态观察，结果提示：（１）ＥＴ灌流离体大鼠心脏时冠脉血流明显减少，心脏组织ＭＤＡ生成，ＬＤＨ漏出显著升高。同时灌流ＣＧＲＰ时冠脉血流显著增加，ＭＤＡ生成和ＬＤＨ漏出量显著降低。（２）ＣＰＢ病人术前ＥＴ水平明显高于术中与术后（Ｐ＜０．０１）心脏复苏后，体内ＥＴ含量达到了最低水平。回ＩＣＵ及术后２４小时体内ＥＴ开始回升。（３）ＣＰＢ期间ＣＧＲＰ无明显变化，术后２４小时，体内ＣＧＲＰ含量明显较术前及术中升高（Ｐ＜０．０５）。文章对上述变化的原因及临床意义进行了简要本文作者单位：１０００３７海军总医院胸心外科、心脏内科讨论分析     

缺血再灌流肾组织内皮素—1及其受体基因表达的实验研究

为了探究内皮素１（ＥＴ１）对肾功能的影响和作用方式，采用斑点杂交和原位杂交方法对大鼠缺血６０分钟再灌注肾组织ＥＴ１及其受体亚型（ＥＴＡ、ＥＴＢ）的基因表达进行了研究。结果发现：再灌流１小时，ＥＴ１、ＥＴＡ、ＥＴＢｍＲＮＡ均明显升高；再灌流２４小时仍维持较高水平。ＥＴ１和ＥＴＡｍＲＮＡ杂交信号再灌流３小时达高峰。ＥＴ１ｍＲＮＡ主要分布肾皮质小血管内皮细胞、髓质肾小管和集合管，ＥＴＡ受体ｍＲＮＡ则分布于上述小血管的平滑肌细胞。ＥＴＢ受体ｍＲＮＡ于再灌流６小时达高峰，主要分布髓质肾小管、集合管。说明缺血再灌流肾内皮素受体亚型上调在皮质以ＥＴＡ为主，在髓质以ＥＴＢ为主，分别与增强表达的ＥＴ１结合导致肾皮质缺血和水钠代谢异常。     

体外循环与内皮素和降钙素基因相关肽的临床与实验研究

为探讨心脏灌流及体外循环（ＣＰＢ）心内直视手术期间的内皮素（ＥＴ）和降钙素基因相关肽（ＣＧＲＰ）的变化及其临床意义。用含有ＥＴ和ＥＴ＋ＣＧＲＰ的ＫＨ液分别对离体大鼠心脏进行灌流并观察冠脉流量、乳酸脱氢酶（ＬＤＨ）及脂质过氧化产物丙二醛（ＭＤＡ）含量。对ＣＰＢ心脏手术病人围术期测定ＥＴ和ＣＧＲＰ含量。结果：（１）大鼠心脏在ＥＴ灌流期间冠脉血流明显减少，ＭＤＡ生成和ＬＤＨ漏出显著升高；同时灌流ＣＧＲＰ则为相反结果。（２）ＣＰＢ心脏手术病人术前ＥＴ含量明显高于术中及术后（Ｐ＜０．０１）；心脏复苏后ＥＴ达到最低水平，进入ＩＣＵ后ＥＴ开始回升。（３）ＣＰＢ期间ＣＧＲＰ含量与术前比无差异，术后２４小时ＣＧＲＰ明显高于术前及术中（Ｐ＜０．０５）。结论为心脏停搏液中似无必要添加ＣＧＲＰ去拮抗ＥＴ，术后早期适量应用ＣＧＥＰ会有所裨益。     

体外循环心内直视手术对心血管调节肽影响的初步临床研究

作者对１５例体外循环心内直视手术病人的内皮素（ＥＴ）、降钙素基因相关肽（ＣＧＲＰ）、神经降压素（ＮＴ）和Ｐ物质（ＳＰ）进行测定，结果提示：（１）ＣＰＢ手术病人术前ＥＴ含量明显高于术中及术后（Ｐ＜０．０１），开放循环心脏复苏后，体内ＥＴ含量达到了最低水平，回ＩＣＵ及术后２４小时，ＥＴ含量回升，但仍明显低于术前；（２）ＣＰＢ期间ＣＧＲＰ无明显变化，术后２４小时体内ＣＧＲＰ水平明显较术前及术中升高（Ｐ＜     

阿魏酸钠对兔心肌缺血再灌注损伤MDA、SOD、ET和NO的影响

目的：观察阿魏酸钠对家兔心肌缺血再灌注损伤的保护效果。方法：１６只兔随机分为非缺血对照组（Ａ组），缺血再灌注常规治疗组（Ｂ组）及缺血于灌注阿魏酸钠治疗组（Ｃ组）。结果：与Ｂ组比较，Ｃ组心肌组织ＭＤＡ含量，血浆ＥＴ水平明显下降（Ｐ〈０．０１），心肌组织Ｔ－ＳＯＤ活性及血清ＮＯ水平显著增高（Ｐ〈０．０１），心肌组织超微结构损伤程度明显减轻，结论：阿魏酸钠可明显减轻家兔心肌缺血再灌注损伤。     

应用分子原位杂交技术检测大鼠烧伤后脏器内皮素mRNA表达

本实验动态观察大鼠烧伤后血浆内皮素（ＥＴ）变化，同时应用分子原位杂交技术检测了大鼠烧伤后心、肺、肝、肾等主要脏器ＥＴ－１ｍＲＮＡ的表达及细胞定位。结果显示，烧伤后血浆内皮素浓度迅速升高，伤后６小时达高峰，２４小时仍维持较高水平。原位杂交显示，烧伤后主要脏器组织ＥＴ－１ｍＲＮＡ表达强度及阳性细胞数迅速增加；其表达峰值的次序为肾、肝、肺、心，且表达阳性细胞种类增加。这可能与内皮素发挥其强大的缩血管作用、调节血流再分布有关，对保证供给休克状态下重要器官的血流灌注有其有益的一面，但ＥＴ－１ｍＲＮＡ的过度表达则可能加重内脏器官的缺血缺氧性损害。     

糖尿病患者肾血流与内皮素及降钙素基因相关肽关系

目的为了解内皮素（ＥＴ）及降钙素基因相关肽（ＣＧＲＰ）与糖尿患者不同阶段时肾血流的关系。方法肾彩色多普勒超声检查确定为糖尿病肾血流正常组（Ａ组）１５例、糖尿病肾血流减少组（Ｂ组）１５例，正常对照组１８例。分别采血测定血浆ＥＴ－１和ＣＧＲＰ浓度。结果Ａ组ＥＴ－１水平低于正常对照组（Ｐ＜０．０１），Ｂ组ＥＴ－１水平高于正常对照组（Ｐ＜０．０１）。二组ＥＴ－１水平与肾动脉收缩期峰值血流速度（Ｖｍａｘ）、肾动脉血流量（Ｑ）呈负相关（Ｐ＜０．０１），与尿白蛋白排泄率（ＵＡＥＲ）呈正相关（Ｐ＜０．０５）。二组的ＣＧＲＰ水平均低于正常组（Ｐ均＜０．０１），但Ａ与Ｂ组的ＣＧＲＰ水平差异无显著性（Ｐ＞０．０５）。未发现ＣＧＲＰ水平与Ｖｍａｘ、Ｑ和ＵＡＥＲ呈相关关系。结论ＥＴ－１在糖尿病不同阶段时对肾血流量的病理生理作用可能不同；糖尿病患者呈现低ＣＧＲＰ血症，但它对不同阶段的糖尿病肾血流的影响尚有待探讨。     

异丙酚对颅脑损伤患者血浆内皮素和降钙素基因相关肽含量的影响

目的 探讨异丙酚对颅脑损伤患者开颅手术间血浆内皮素（ＥＴ）和降钙素基因相关肽（ＣＧＲＰ）含量的影响。方法 急性颅脑损伤（ＡＣＩ）患者４０例,随机分为观察组（异丙酚组,ｎ＝２０,Ａ组）和对照组（γ－羟基丁酸钠组,ｎ＝２０,Ｂ组）以放射免疫分析方法测定了４０例ＡＣＩ患者麻醉前后血浆ＥＴ,ＣＧＲＰ含量,并以４０例健康献血者为术前对照。结果 ＡＣＩ患者术前ＥＴ及ＥＴ／ＣＧＲＰ明显高于正常对照组（Ｐ〈０．０     

缺血再灌流肾组织内皮素—1动态变化的实验研究

在大鼠肾缺血６０分钟再灌注的模型上观察不同时相肾静脉血、肾皮质、外髓和内髓的内皮素１（ＥＴ１）浓度变化，肾组织ＥＴ１光镜和电镜免疫组织化学变化。结果发现：缺血再灌流肾组织ＥＴ１基因表达及分泌明显增强，主要分布在血管内皮细胞及平滑肌细胞、系膜细胞、肾小管上皮细胞。其分布特点与细胞类型和活性有关。本实验结果提示了缺血再灌注肾内ＥＴ１的变化规律。     

一氧化氮在急性缺血性肾衰中作用的实验研究

采用左肾动脉夹闭６０分钟再灌注致缺血性肾衰模型，观察再灌注后肾脏皮质、外髓、内髓中ＮＯ（ＮＯ稳定代谢产物）的动态变化；再灌注后加用ＮＯ底物（Ｌ－精氨酸）或ＮＯ生成抑制剂（Ｌ－ＮＮＡ）对肾脏ＮＯ生成及肾功能的影响。结果表明：再灌注后肾组织ＮＯ含量显著下降，再灌注２４小时无明显恢复。使用Ｌ－ＮＮＡ可进一步减少ＮＯ２生成，加重肾功能损害；Ｌ－精氨酸对肾脏ＮＯ２生成和肾功能均无显著改善。结果提示：再灌注后ＮＯ的生成减少，ＮＯ的生成抑制源于肾脏ＮＯ生成能力的损害，ＮＯ的减少可加重肾功能损害。     

肾缺血/再灌注时肾组织损伤及细胞凋亡的实验研究

目的：检测肾缺血／再灌注不同时问点肾组织、功能损伤及细胞凋亡的变化，探讨细胞凋亡在肾缺血／再灌注损伤中发生的机制。方法：应用苦味酸法和二乙酰一肟反应法测定大鼠肾缺血／再灌注不同时间点血肌酐和尿素氮值检测肾功能变化，用HE染色光镜下观察缺血／再灌注石蜡包埋切片肾组织损伤形态学改变，用酚／氯仿抽提小片断DNA，在琼脂糖电泳上测定不同时间点DNA Ladder及利用原位凋亡检到法观察各时间点TUNEL阳性细胞数检测细胞凋亡情况。结果：肾功能检测发现，缺血45min后血肌酐和尿素氮值明显增高和正方对照差异显(P＜0.05)，再灌注早期上升缓慢，3h后再次增高，组内对比差异显(P＜0．05)。HE染色光镜下观察肾组织细胞以近端肾小管变性为主、坏死轻微，缺血／再灌注各时间点组织损伤变化与肾功能变化规律相一致。琼脂糖电泳和TUNEL检测在缺血45min再灌注3h时可测到DNA Ladder和TUNEL阳性细胞增加，再灌注12h细胞凋亡最明显。结论：肾缺血／再灌注可引起肾组织轻、中度的损伤和明显的肾功能损害；肾缺血／再灌注后期肾组织及功能损伤加重可能与细胞凋亡的发生有关。     

Nebivolol reduces experimentally induced warm renal ischemia reperfusion injury in rats

Ischemia/reperfusion injury, which is commonly seen in the field of renal surgery or transplantation, is a major cause of acute renal failure. The objective of the present study was to examine the role of nebivolol in modulating peroxynitrite species-induced inflammation and apoptosis after renal warm ischemia/reperfusion injury in rats. The present study was designed to investigate the effects of nebivolol on the renal warm ischemia/reperfusion injury in rats treated with the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester. After right nephrectomy, nebivolol was administered for 15 days. On the 16(th) day, ischemia was induced in contra lateral kidney for 45 min, followed by reperfusion for 24 hr. Renal function, inflammation, and apoptosis were estimated at the end of 24 hr reperfusion. Nebivolol improved the renal dysfunction and reduced inflammation and apoptosis after renal ischemia/reperfusion injury. In conclusion, nebivolol shows potent anti-apoptotic and anti-inflammatory properties due to its NO-releasing property. These findings may have major implications in the treatment of human ischemic acute renal failure.     

梗阻性黄疸大鼠血浆和肾组织内皮素含量的变化及与肾功能关系的研究

目的：了解血浆，肾组织内皮素（ET）在梗阻性黄疸（OJ）大鼠模型上不同梗阻时间的变化情况，探讨循环ET和肾内ET与梗阻性黄疸时肾功能损害的关系。方法：胆总管结扎及假手术组各32只Wistar大鼠分别于术后5，10，15，20d（每小时n=8)采用放射免疫法测定血浆和肾皮质，髓质细胞匀浆ET含量，同时测定血清肌酐（Cr)，尿素氮（BUN）和直接胆红素（DB）浓度，并对肾脏行光镜下病理形态学观察。结果；血浆ET浓度及肾皮质，髓质ET含量在梗阻5d即升高，且随OJ时间延长进一步升高，伴有血清Cr,BUN,DB的升高和肾脏病毒形态的进行性改变。血浆ET，肾皮质ET在大部分或部分时相与Cr,BUN呈明显正相关，血浆ET在大部分时相与DB呈明显正相关。结论：梗阻性黄疸时循环和肾内ET水平持续性升高；血浆和肾皮质ET的升高可能参与了肾脏滤过功能的损害；肾髓质ET的升高可能是导致OJ早期尿浓缩功能异常的介质之一；高胆红素血症可能是血浆ET升高的原因之一。     

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.     

Changes in expression of sodium cotransporters and aquaporin-2 during ischemia-reperfusion injury in rabbit kidney

Ischemic renal injury is associated with defects in transport functions of the proximal tubules and urinary concentration ability. To determine whether alterations in expression of various transporter genes contribute to an impairment in renal functions, the expression of various solute transport genes was analyzed in renal cortex and medulla of rabbits with ischemic acute renal failure. Rabbits were subjected to 60 min of renal pedicle clamping followed by 24, 48, or 72 h of reperfusion. Urine volume and glomerular filtration rate were markedly decreased, which were accompanied by an increase in serum creatinine level and fraction Na+ excretion. Glucosuria and phosphaturia were evident during reperfusion periods. These alterations in renal functions were persisted to 72 h after reperfusion. The Na+-dependent uptakes of glucose and phosphate by brush border membrane vesicles were inhibited by 24 h of reperfusion. mRNA levels for Na+-glucose, Na+-phosphate, and Na+-succinate cotransporter analyzed by RT-PCR were not changed by 60 min of ischemia alone, but were significantly reduced by 24 h of reperfusion. mRNA levels for apical Na+-K+-2Cl- cotransporter, NaCl cotransporter, and turea transporter in the medulla were not changed during reperfusion. Protein levels for AQP2 in the medulla, but not AQP1 in the cortex, analyzed by Western blot were significantly reduced at 24 h after reperfusion. These results suggest that reductions in expression of Na+-cotransporter genes in the proximal tubules may be important factors in the impairment in Na+-dependent reabsorption of solutes and that decrease in AQP2 protein may be involved in defect in urinary concentration ability in rabbits with ischemic acute renal failure.     

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.