雷帕霉素对肾脏缺血再灌注损伤的影响

移植肾在经历缺血再灌注损伤后可以产生不同程度的损伤,而雷帕霉素作为临床上常用的免疫抑制剂,又可对再灌注的移植肾产生多方面的影响.本文就雷帕霉素对肾脏缺血再灌注损伤的影响作一综述.     

七氟醚对大鼠急性肾缺血-再灌注损伤的保护作用

目的探讨七氟醚对急性肾缺血-再灌注损伤的保护作用及其机制。方法SD大鼠18只,随机均分为缺血-再灌注组(I/R组)、七氟醚组(S组)和对照组(C组)。建立大鼠急性肾缺血-再灌注损伤模型,缺血-再灌注后3h分别检测血清尿素氮(BUN)、肌酐(Cr)、超氧化物歧化酶(SOD)、丙二醛(MDA)及观察肾组织的病理学变化。结果与C组比较,I/R组和S组血清BUN、Cr水平显著增加(P<0.05),但S组BUN、Cr低于I/R组(P<0.05)。与I/R组比较,S组SOD显著升高,MDA显著降低(P<0.05)。S组肾组织病理损伤分级明显低于I/R组(P<0.05)。结论七氟醚对大鼠急性肾缺血-再灌注损伤具有保护作用,抑制氧自由基反应可能是其重要机制。     

Carnitine as a preventive agent in experimental renal ischemia-reperfusion injury

Reactive oxygen species generated during the reperfusion of ischemic kidney, as well as any other tissue, cause lipid peroxidation damaging the cell membrane. The aim of this study was to investigate the effect of carnitine in reperfusion injury of the kidney. Male albino rabbits were subjected to unilateral renal 1-h warm ischemia followed by 15 min of reperfusion. Group I (n=9): control group received 3 cc of isotonic saline solution and group II (n=9): carnitine group received 100 mg/kg of carnitine. Blood samples were collected at the 15th min of reperfusion from the left renal vein selectively. Preischemic and post-reperfusion serum and renal tissue MDA levels were measured by thiobarbituric acid reactive substances (TBARS) spectrophotometric analysis. The preischemic serum and tissue MDA values (sham values) for groups I and II were statistically comparable (P > 0.01). Serum and tissue MDA levels were markedly elevated after 15 min of reperfusion in group I (P < 0.01), while the values remained in the baseline levels following reperfusion in group II (P > 0.01). In group I, the major histological differences observed in the reperfused kidneys were marked edema and congestion whereas glomerular and tubular cellular integrity were well preserved in group II. Pre-treatment with carnitine in solid organ transplantations, preschock states, surgical procedures that require temporary vascular clamping etc. may be helpful to minimize the reperfusion injury in the involved tissue, reducing morbidity and mortality. Received: 22 May 2000 / Accepted: 1 February 2001     

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

Background

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

Materials and methods

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

Results

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

Conclusions

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

Pretreatment with sildenafil alleviates early lung ischemia-reperfusion injury in a rat model

Background

Lung ischemia-reperfusion (I/R) injury plays an important role in lung transplantation. Less well known is the role of sildenafil in lung I/R injury; therefore, we attempted to determine whether sildenafil could alleviate lung apoptosis and tissue injury in a rat model.

Methods

Forty male Sprague-Dawley rats were randomized into four groups: saline + sham, saline + I/R, sildenafil + sham, and sildenafil + I/R groups. Three hours before the operation, each rat received normal saline or sildenafil (10 mg/kg) by lavage. The animals designed to I/R injury were subjected to 2 h of ischemia induced by occlusion of left pulmonary artery, veins, and bronchus, followed by reperfusion for 2 h. The lung tissue was harvested for the analysis of the expression of Bax, Bcl-2, p53, caspase 3, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and wet/dry (W/D) weight ratio.

Results

Compared with the saline + sham group, the saline + I/R group had significant increases in Bax, p53, Bax/Bcl-2 ratio, caspase 3, IL-6, TNF-α, and W/D weight ratio but a decrease in Bcl-2 (P < 0.05). Compared with the saline + I/R group, sildenafil + I/R group had significant decreases in Bax, p53, Bax/Bcl-2 ratio, caspase 3, IL-6, TNF-α level, and W/D weight ratio but an increase in Bcl-2 expression (P < 0.05). Compared with the sildenafil + sham group, there were significant increases in p53 and TNF-α expression in the sildenafil + I/R group (P < 0.05).

Conclusions

Pretreatment with sildenafil alleviates lung apoptosis and tissue injury in a rat model.     

肾脏固有树突状细胞在肾缺血-再灌注期间的变化

目的  探讨在肾脏缺血-再灌注损伤(IRI)期间肾脏固有树突状细胞(rDC)的变化。方法  采用C57BL/6J小鼠建立双侧肾脏热缺血模型,再灌注24 、48 h后取肾组织制备单细胞悬液,流式细胞仪分析CD45⁺细胞和CD11c⁺rDC的比例变化;采用绿色荧光蛋白和白喉毒素受体标记(CD11c⁺GDTR)的小鼠肾组织制作单细胞悬液,流式细胞仪分析CD11c⁺rDC的比例及表型;采用CD11c⁺GDTR小鼠建立双侧肾脏热缺血模型,再灌注24 h后取肾组织制备单细胞悬液,MACS磁珠富集CD45⁺细胞,经流式细胞仪分析rDC表面共刺激分子表达情况。结果  再灌注24 h后C57BL/6J小鼠肾脏内CD45⁺细胞比例明显增加,48 h后其比例进一步升高,再灌注24 h后CD11c⁺rDC数量同样持续升高,但其占CD45⁺细胞的比例出现明显下调,48 h后恢复并较Sham组轻度升高;CD11c⁺GDTR小鼠正常肾脏CD45⁺细胞比例低于1%,其中约40%为CD11c⁺的肾脏rDC,主要呈CD11b^intF4/80^-MHC Ⅱ⁺;再灌注24 h后CD11c⁺F4/80^-亚群rDC表面共刺激分子CD40、CD80、CD86均显著升高。结论  热IRI后rDC比例、数量及其表面共刺激分子表达均增加,提示热IRI后肾脏rDC浸润增多且表型成熟。     

Earlier renal fibrosis aggravates acute kidney injury induced by ischemia reperfusion in mice

Objective To investigate the influence of earlier renal fibrosis on ischemia and reperfusion induced acute kidney injury. Methods Male C57BL/6 mice at eight to twelve weeks old age were divided into 4 groups randomly: (1)Sham (n=3); (2)Unilateral ureter obstruction (UUO, n=6): UUO for 3 days (UUO3d, n=3) and UUO for 5 days (UUO5d, n=3);(3)Ischemia and reperfusion (IR, n=7): bilateral kidney ischemia for 40 minutes followed by 24 hours of reperfusion; (4)UUO for 3 days plus IR (UUO3d+IR, n=6): bilateral kidney ischemia after UUO 2 days for 40 minutes followed by 24 hours of reperfusion, and the real time for UUO was 3 days. Pathologic analysis for acute or chronic injury was performed on paraffin embedded kidney sections with hematoxylin and eosin (HE) or Masson staining. Apoptosis was detected by immunohistochemistry(IHC) and Western blotting with anti-caspase-3 antibody, and proliferation was observed by IHC with anti-ki67 antibody. Results On kidney sections with HE or Masson staining, it showed that the chronic kidney lesions and fibrosis got more severe as time of UUO prolonged from 3 days to 5 days; the area of matrix deposition increased in UUO5d and UUO3d mice significantly compared to Sham mice (P＜0.05) and was smaller in UUO3d mice compared with UUO5d mice obviously (P＜0.05). Acute kidney injury could be observed in UUO3d+IR mice, such as massive inflammatory cells infiltration, tubules dilation, brush border disappearance, tubular epithelial cells vacuolar degeneration, necrosis, casting formation, coexisting with chronic lesions: thinner cortex, broadened interstitial space, and increased blue stained matrix. Acute kidney injury score in UUO3d+IR mice was higher than that in IR mice significantly (P＜0.05), and serum creatinine level increased significantly in UUO3d+IR mice compared to Sham mice (P＜0.05). Caspase-3 expression increased and ki67 positive tubular cells decreased in UUO3d+IR mice than those in IR mice obviously (P＜0.05). Conclusion Earlier renal fibrosis aggravates acute kidney injury induced by ischemia reperfusion in mice through increasing apoptosis and decreasing proliferation of tubular epithelial cells.     

丙泊酚对大鼠肾缺血-再灌注期血清白细胞介素-8的影响

目的观察丙泊酚对大鼠肾缺血-再灌注期血清白细胞介素-8(IL-8)的合成和释放的影响,并探讨其肾保护机制。方法选用12~14周雄性大鼠75只,随机分为三组,每组25只,以无创动脉夹夹闭双侧肾蒂60min制备急性肾缺血-再灌注模型。A组为肾缺血-再灌注组,B组为丙泊酚处理组,C组为假手术组。各组设立五个时间观察点:缺血前10min(T0),缺血60min(T1),再灌注1h(T2)、3h(T3)、6h(T4),每个时间点5只大鼠。C组:肾脏缺血60min,缺血前5min从股静脉注射丙泊酚20mg/kg,继之经微量泵持续输入丙泊酚(0·5mg/ml)50mg·kg-1·h-1,持续60min;A、B组以等容生理盐水取代丙泊酚,但A组不夹闭双侧肾蒂,术中保持大鼠呼吸、循环稳定。各组大鼠存活至预定时间后再次麻醉取标本,测定血浆丙二醛(MDA)、超氧化物歧化酶(SOD)、血清IL-8,同时用光学显微镜观察肾组织形态学改变及肾小管损伤情况。结果血浆MDA在C组T1~T4时无明显变化,同A组相似,较B组相应时点显著降低,而B组T1~T4时较T0时及A组各时点显著升高;SOD则呈相反变化;C组T1~T3时血清IL-8无明显变化,仅在T4时较T0时和A组有显著升高,而B组在T1~T4时分别增加1·73、2·50、2·76、2·89倍,同C组和A组相比有显著性差异;光镜下观察发现B组肾小管上皮细胞变性、坏死,细胞脱落,肾小管管腔变窄,肾间质水肿、充血伴炎性细胞浸润明显;而C组以肾小管肿涨为主,个别呈坏死样改变,肾间质水肿、充血、炎性细胞浸润不明显。结论丙泊酚除了有抗氧作用外,还能有效地抑制血清IL-8合成和释放,这可能是丙泊酚减轻肾缺血-再灌注损伤的机制之一。     

促红细胞生成素对大鼠移植肾缺血-再灌注损伤的防护作用

探讨促红细胞生成素(erythropoietin,EPO)对大鼠移植肾缺血-再灌注损伤(ischemia-reperfusion injury,IRI)的保护作用.方法 采用BN大鼠和Lewis大鼠,分别随机分为实验组和对照组,每组各15只.BN大鼠作为供体,Lewis大鼠为受体,建立单侧原位大鼠肾移植模型.实验组受体大鼠术后立即腹腔注射重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)1 000 U/kg,对照组大鼠同样予腹腔注射等量生理盐水.两组受体大鼠在术后5d剪尾取血,检测血清肌酐(Scr)水平.同时将移植肾取出,肾组织行病理切片苏木素-伊红(HE)染色、过碘酸-雪夫(periodic acid Schiff,PAS)染色、马松(Masson)染色和过碘酸六胺银(periodic acid-silver methenamine,PASM)染色,观察肾组织病理学改变情况.结果 实验组受体大鼠术后Scr水平为(102±3)μmol/L,对照组为(369±7)μmol/L,两者比较差异有统计学意义(P<0.05).两组受体大鼠移植肾均出现肾小管坏死改变.对照组移植肾组织病理切片主要表现为大片肾组织坏死,提示出现严重的急性排斥反应、肾小管坏死及动脉损伤;实验组肾组织病理切片主要表现为肾被膜下小灶性肾组织凝固性坏死;与对照组相比,实验组肾组织坏死面积较小,提示急性排斥反应程度较轻.结论 肾移植术后早期使用EPO进行预处理可抑制肾脏IRI炎症反应,减少细胞凋亡,缓解移植后IRI.     

Effects of trapidil on renal ischemia-reperfusion injury

There is increasing evidence to suggest that reactive oxygen and nitrogen species play a role in the pathogenesis of renal ischemia-reperfusion (I/R) injury. This study was designed to determine the possible protective effects of trapidil treatment against oxidative and nitrosative tissue injury of kidney induced by I/R.A renal I/R injury was induced by a left renal pedicle occlusion by ischemia for 45 minutes, followed by 1 hour of reperfusion with contralateral nephrectomy in I/R and I/R + trapidil groups. Trapidil (8 mg/kg intravenously) was administrated immediately before reperfusion phase. At the end of the reperfusion period, rats were killed. Then, renal tissue samples were taken for biochemical analysis and histopathological evaluation, and blood samples were obtained to determinate serum urea, aspartate aminotransferase (AST), and tumor necrosis factor-α (TNF-α) levels. Ischemia-reperfusion injury caused significant increases in myeloperoxidase activity and malondialdehyde and 3-nitrotyrozine levels in renal tissue and elevated serum urea, AST, and TNF-α levels. In addition, severe deterioration of renal morphology was seen in the I/R group. Trapidil treatment significantly reduced in biochemical parameters, as well as serum urea, AST, and TNF-α levels. Furthermore, renal tissue injury was markedly attenuated with trapidil treatment. These data suggest that reactive oxygen species and reactive nitrogen species play a causal role in I/R-induced renal tissue, and trapidil has a renoprotective effect against oxidative and nitrosative kidney damage.     

参芎注射液对肾缺血再灌注损伤大鼠的保护作用

目的观察参芎注射液对肾缺血再灌注损伤大鼠肾组织核因子-κB（NF-κB）、肿瘤坏死因子-α（TNF-α）、丙二醛（MDA）水平和超氧化物歧化酶（SOD）活性的影响,探讨其肾保护作用机制。方法将24只SD大鼠随机分为假手术对照组、缺血再灌注组、参芎预处理组,每组8只。免疫组织化学法检测各组大鼠肾组织NF-κB蛋白表达,酶联免疫吸附法检测肾组织TNF-α含量,用MDA和SOD试剂盒分别检测肾组织MDA含量和SOD活性。结果①与假手术对照组相比,缺血再灌注组大鼠肾组织NF-κB蛋白表达、TNF-α和MDA含量明显升高,差异均有统计学意义（P〈0．01）;而SOD的活性明显降低,差异有统计学意义（P〈0．01）。②与缺血再灌注组相比,参芎预处理组大鼠肾组织NF-κB蛋白表达、TNF-α和MDA含量降低,差异均有统计学意义（P〈0．05或P〈0．01）;而SOD的活性明显升高,差异有统计学意义（P〈0．01）。结论参芎注射液对肾缺血再灌注损伤有一定的保护作用,其机制可能与抗自由基氧化损伤以及抑制炎性细胞因子NF-κB和TNF-α的表达有关。     

Effect of rapamycin on renal ischemia-reperfusion injury in mice

The aim of this study was to determine the effect of rapamycin on renal ischemia-reperfusion injury (IRI) in mice. Renal IRI was induced in male BALB/c mice by clamping both renal pedicles for 45 min. The mice were treated with either vehicle or rapamycin (2 mg/kg/day) by oral gavage, starting 1 day before the IRI and continued daily till killing. The mice were killed on days 1, 3 and 7 after the operation. The severity of the renal IRI was assessed by serum creatinine levels and renal histology. Proliferation of renal tubular cells was quantified by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). One day after the IRI, the serum creatinine levels of rapamycin-treated mice were significantly higher than those of the vehicle-treated mice. Kidney sections from rapamycin-treated mice showed more marked tubular damage and significantly lower number of PCNA-positive cells. The number of PCNA-positive cells in the rapamycin-treated mice remained significantly lower on day 3 after the IRI. By day 7 after the IRI, the serum creatinine levels, renal histology and positive PCNA staining in the kidney sections became similar between the two treatment groups. We conclude that in this murine model of renal IRI, rapamycin treatment aggravates renal IRI during the first 3 days after the insult. This effect might be mediated, at least partly, through inhibition of renal tubular cell proliferation.     

缺血再灌注损伤皮瓣组织中金属硫蛋白含量变化

目的　观察缺血再灌注损伤皮瓣组织中金属硫蛋白 (metallothionein ,MT)的含量变化。方法　 16只大鼠随机分为对照组 (n =8)和缺血再灌注损伤组 (n =8)。在大鼠腹壁浅血管为蒂的岛状皮瓣缺血再灌注损伤模型上 ,用10 9Cd血红蛋白饱和法和硫代巴比妥酸法测定皮瓣组织中MT及丙二醛(MDA)含量 ,比色法测定皮瓣组织过氧化物酶 (MPO )活性。结果　缺血再灌注损伤组在缺血 8h、再灌注 12h、2 4h时皮瓣组织中MDA水平分别较对照组高 41.7%、111.4%、13 5.7% ,MPO水平分别较对照组高 72 .1%、2 18.9%、2 96.0 % ,MT含量分别较对照组高 42 .6%、52 .8%、10 2 .3 % (P <0 .0 5或P<0 .0 1)。结论　皮瓣组织中MT含量增多 ,可能与皮瓣缺血再灌注损伤有关     

小鼠急性缺血-再灌注肾损伤模型的建立及体会

目的观察应用小鼠制备急性缺血一再灌注性肾损伤模型的效果。方法应用微型动脉夹夹闭小鼠双侧肾动脉制备急性缺血一再灌注肾损伤模型,其中两组分别于术后24h和48h后处死观察肾功能及肾脏病理变化．另一组观察其病情及存活情况14天。结果各次造模成功率均达85％以上;术后24h及48h实验组血清肌酐（Scr）和血尿素氮（BUN）水平明显升高,与对照组比较差异有统计学意义（P〈0．01）：实验组肾脏外观出现典型“大白肾”表现,镜下出现典型急性肾小管坏死表现,并有较多炎症细胞浸润,肾小管组织学评分与对照组比较差异有统计学意义（P均〈0．01）;实验组在观察期间逐渐出现典型急肾衰竭表现,至14天末,死亡率达91．7％,而对照组全部正常存活。结论应用微型动脉夹夹闭小鼠双侧肾动脉可制备稳定急性缺血一再灌注肾损伤模型,而且成功率较高。     

缺血预处理在移植肾缺血-再灌注损伤中的应用进展

肾移植相对于其他器官移植术后疗效更为显著,但肾缺血-再灌注损伤（IRI）等术后并发症严重影响受者生存率和生存质量,如何减轻移植肾IRI成为了肾移植领域当前的研究重点。目前认为缺血预处理使移植肾适应缺血是预防IRI发展的有效方法之一,但具体机制尚未完全清楚。本文就缺血预处理在IRI中的应用,缺血预处理对移植肾IRI的调控机制,包括细胞水平的调控和细胞内信号通路的调控,以及缺血预处理的临床应用价值和前景进行综述,以期为改善移植肾IRI,提升肾移植受者和移植肾存活率,改善受者生存质量提供参考。     

肝脏缺血-再灌注损伤的机制探讨

肝脏缺血-再灌注损伤包括两个不同阶段:早期发生在再灌注2～4 h内,主要由增多的氧自由基产物所介导;晚期发生于再灌注后6 h或更久,主要由于炎症反应所致,并导致肝脏的进一步损害.肝脏的肝脏缺血-再灌注损伤是一个复杂的、多因素的过程.本综述回顾了当前对肝脏缺血-再灌注损伤的理解及研究进展,分别从微循环水平、细胞水平、分子水平阐述其机制.     

巨噬细胞在移植肾纤维化中的作用研究进展

缺血-再灌注损伤、排斥反应、钙调磷酸酶抑制剂造成的肾毒性等因素会在肾移植术后使肾细胞外基质过度积聚,逐渐造成移植肾纤维化,最终导致肾衰竭。近年来,巨噬细胞在移植肾纤维化中的作用机制逐渐受到关注,有研究表明哺乳动物雷帕霉素靶蛋白抑制剂等药物可以通过巨噬细胞途径减缓肾移植术后移植肾纤维化。本文就移植肾纤维化的主要病因及病理生理学机制、不同巨噬细胞在移植肾纤维化进展中的作用、外周募集巨噬细胞和肾驻留巨噬细胞对肾损伤区域的浸润、巨噬细胞对肌成纤维细胞的诱导作用及巨噬细胞相关的移植肾纤维化潜在治疗方案进行综述,以期为巨噬细胞在移植肾纤维化中的研究提供参考。     

七氟醚对在体大鼠肺缺血-再灌注损伤的影响

目的研究七氟醚对在体大鼠肺缺血-再灌注(I-R)损伤的影响。方法40只Wistar大鼠建立在体大鼠肺I-R模型,随机分为四组,每组10只:A组,假手术组,开胸后机械通气120 min;B组,I-R组,阻断左肺门60 min,开放再通气60 min;C组,七氟醚加I-R组,缺血前吸入1 MAC七氟醚30 min,开放再通气同时吸入1 MAC七氟醚60 min;D组,七氟醚组,持续吸入1 MAC七氟醚120min。观察各组实验结束时肺组织的湿/干重比(W/D)、肺丙二醛(MDA)、超氧化物歧化酶(SOD)和肺组织病理学的改变。结果B组及C组肺W/D较A组和D组显著升高(P<0.01,P<0.05),SOD含量显著低于A组和D组(P<0.05);B组肺MDA含量较A组和D组显著升高(P<0.01),C组肺MDA含量较B组低(P<0.05);C组肺W/D、肺MDA显著低于B组(P<0.05),SOD高于B组(P<0.05);病理切片见B组、C组部分肺泡结构破坏,肺泡间隔增宽,肺泡腔内水肿并有出血,以B组改变较为严重,炎症积分显著高于C组(P<0.01)。结论七氟醚对在体大鼠肺I-R损伤有一定的保护作用。     

雷帕霉素影响肾缺血再灌注后组织损伤和修复的实验研究

目的研究雷帕霉素对肾缺血再灌注（IR）后不同时期肾小管上皮细胞凋亡及增殖、修复的影响。方法体质量为25～30 g BALB/c小鼠45只随机分为手术对照组、IR对照组和雷帕霉素组。建立阻断小鼠左侧肾蒂30 min后切除右侧肾模型。雷帕霉素组术前及术后每日给予0.5 mL雷帕霉素和生理盐水混悬液（1 mg∶10 mL）灌胃,IR对照组给予等量生理盐水灌胃。术后1、3和7 d每组各处死5只小鼠取全血及肾组织,检测血清肌酐水平,HE染色评价组织病理学改变。采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法检测肾小管上皮细胞凋亡,通过免疫组织化学检测肾小管上皮细胞增殖细胞核抗原以比较组间肾小管上皮细胞增殖修复差异。结果雷帕霉素组术后1 d肾功能好于IR对照组（P〈0.05）,但在7 d时却较IR对照组差（P〈0.05）。IR对照组和雷帕霉素组术后3个时期的肾组织病理学改变均较手术对照组严重（P〈0.05）,但前两组间损伤病理学评分均无明显差异（P〉0.05）。术后1 d和3 d时,雷帕霉素组凋亡细胞数明显少于IR对照组（P〈0.05）。术后1、3和7 d雷帕霉素组肾小管上皮细胞增殖细胞核抗原表达水平均显著低于IR对照组（P〈0.05）。结论肾缺血再灌注损伤早期以肾小管上皮细胞凋亡为主,后以细胞增殖修复为主。雷帕霉素因具有抗凋亡和抗增殖的双重作用,可以减轻缺血再灌注对肾功能损伤,但却不利于以后的组织修复。