Protective effect of trapidil on long-term histologic damage in a rat model of testicular ischemia-reperfusion injury

Objectives  Trapidil is an antianginal compound with a broad spectrum of pharmacological activities. In recent years, it has been used successfully to decrease ischemia-reperfusion injury in several organ systems. We evaluated the effect of trapidil on the long-term histologic damage in testicular ischemia-reperfusion injury. Methods  Adult male Wistar rats were divided into three groups of six rats each. One group underwent 2 h of testicular torsion; one received pretreatment with trapidil before detorsion; and one group underwent sham operation. All rats underwent bilateral orchiectomy 60 days after the experiment. The mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score were determined by histological examination of each testis. Results  Testicular torsion–detorsion caused a significant decrease in the mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score in the ipsilateral testes, but not in the contralateral testes. The animals treated with trapidil had a significant increase in these histological parameters as compared to the torsion–detorsion group. Conclusion  Trapidil administration before reperfusion may have the potential to decrease the long-term histologic damage that occurs after experimental testicular torsion. Trapidil is used as an antianginal drug and additional clinical studies are required to elucidate the protective role of trapidil in patients with testicular torsion.     

The long-term protective effects of short-interval postconditioning in testicular ischemia-reperfusion injury in rats

AimEven with prompt diagnosis and treatment, testicular torsion may lead to infertility and atrophy after testicular salvage. The aims of this study were to investigate the long-term protective effects of short-interval postconditioning on testicular atrophy and to optimize the reperfusion period.Materials and MethodsForty adult male rats were divided into 5 subgroups: sham operated; torsion + detorsion; torsion + postconditioning, 5 seconds (PC5); torsion + postconditioning, 10 seconds; and torsion + postconditioning, 20 seconds. Torsion was created by rotating the left testis 1080° counterclockwise and then fixing the testis to the scrotum with 3 sutures. Torsion was maintained for 4 hours. The testicular artery was visualized, and an atraumatic vascular clamp was applied to prevent reperfusion in all study groups. Detorsion of the testis was then performed. In the torsion + detorsion group, the clamp was released just after detorsion. In all the other intervention groups, the subsequent procedures were repeated 10 times. In the PC5 group, the clamp was released for 5 seconds and applied for 10 seconds; in the torsion + postconditioning, 10 seconds group, the clamp was released for 10 seconds and applied for 10 seconds; and in the torsion + postconditioning, 20 seconds group, the clamp was released for 20 seconds and applied for 10 seconds. Then, reperfusion was allowed. After 60 days, rats in all study groups were killed, both testes were removed, and the histopathology was evaluated. The χ² test was used for statistical analysis.ResultsCompared with the other groups, the extent of tissue injury determined by histopathologic grades according to Cosentino et al (J Androl. 1986;7:23-31) was significantly less in group PC5 (P < .05).ConclusionWe conclude that short-interval postconditioning can protect against long-term testicular reperfusion injury. Furthermore, the optimal time for reperfusion during postconditioning was 5 seconds in our rat model of testicular torsion. This technique seems easily applicable, and evidence suggests that similar techniques may be useful during testicular surgery.     

Aging aggravates long-term renal ischemia-reperfusion injury in a rat model

Aim

Ischemia-reperfusion injury (IRI) has been considered as the major cause of acute kidney injury and can result in poor long-term graft function. Functional recovery after IRI is impaired in the elderly. In the present study, we aimed to compare kidney morphology, function, oxidative stress, inflammation, and development of renal fibrosis in young and aged rats after renal IRI.

Materials and methods

Rat models of warm renal IRI were established by clamping left pedicles for 45 min after right nephrectomy, then the clamp was removed, and kidneys were reperfused for up to 12 wk. Biochemical and histologic renal damage were assessed at 12 wk after reperfusion. The immunohistochemical staining of monocyte macrophage antigen-1 (ED-1) and transforming growth factor beta 1 (TGF-β1) and messenger RNA level of TGF-β1 in the kidney were analyzed.

Results

Renal IRI caused significant increases of malondialdehyde and 8-hydroxydeoxyguanosine levels and a decrease of superoxide dismutase activity in young and aged IRI rats; however, these changes were more obvious in the aged rats. IRI resulted in severe inflammation and tubulointerstitial fibrosis with decreased creatinine (Cr) clearance and increased histologic damage in aged rats compared with young rats. Moreover, we measured the ratio of Cr clearance between young and aged IRI rats. It demonstrated that aged IRI rats did have poor Cr clearance compared with the young IRI rats. ED-1 and TGF-β1 expression levels in the kidney were significantly higher in aged rats than in young rats after IRI.

Conclusion

Aged rats are more susceptible to IRI-induced renal failure, which may associate with the increased oxidative stress, increased histologic damage, and increased inflammation and tubulointerstitial fibrosis. Targeting oxidative stress and inflammatory response should improve the kidney recovery after IRI.     

大鼠肺缺血再灌注损伤长期存活模型的建立

目的 建立一种简单、稳定的大鼠肺缺血再灌注损伤(LIRI)长期存活模型.方法 将84只健康SD大鼠随机分为2组:Ⅰ组为假手术组,Ⅱ组为肺缺血再灌注组(每组n=42只).两组分别于开胸后、缺血1 h后再灌注0、2、4h、1、3、7 d取肺组织行髓过氧化物酶(MPO)活性、肺湿干比(W/D ratio)检测和肺泡Ⅱ型细胞(ATⅡ)的电镜超微结构评价;取支气管肺泡灌洗液检测肺通透性指数(LPI).结果 手术成功率达100%.Ⅱ组与Ⅰ组比较,缺血再灌注后2、4 h、1 d的MPO、LPI、W/D比差异均有统计学意义(P<0.01),开胸后、再灌注后0 h、3、7 d两组比较差异无统计学意义(P>0.05).ATⅡ的超微结构显示,再灌注4 h后损伤最严重,再灌注1 d即出现明显的修复过程,再灌注7 d基本恢复正常结构水平.结论 本模型简单、可靠,LIRI后相关肺损伤指标和ATⅡ超微结构损伤变化特点吻合.     

The effect of astaxanthine on ischemia-reperfusion injury in a rat model

BackgroundWe aimed to compare biochemical and histopathological findings of astaxanthin's potential effects on oxidative stress in ischemia/reperfusion damage (I/R).MethodsThirty-two rats were randomly divided into four groups: control group; I/R group; I/R + treatment group; drug group. Astaxanthin was orally administered to groups C and D for 14 days. In groups B and C, the femoral artery was clamped for 2 h to form ischemia. The clamp was opened, and reperfusion was performed for 1 h. In all groups, 4 ml of blood sample through intracardiac puncture and gastrocnemius muscle tissue samples were collected. Serum and tissue samples were analyzed by measuring malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAC), and total oxidative level (TOL). Necrosis, inflammation, and caspase-3 in muscle tissue collected for histopathological examination were evaluated.ResultsTissue MDA, SOD and TOL values significantly differed between groups. Serum MDA, SOD, TOL and TAC values significantly differed between groups. On necrosis examination, there was a significant difference between groups B and C. Although signs of inflammation significantly differed between groups, there was no significant difference between groups A and C and groups A and D. Although there was a significant difference in caspase-3 results between groups, there was no significant difference between groups A and C.ConclusionsThe use of astaxanthin before and after surgery showed preventive or therapeutic effects against I/R damage.     

Erdosteine improves oxidative damage in a rat model of renal ischemia-reperfusion injury

The aim of the present study was to determine the effects of erdosteine, a new antioxidant and anti-inflammatory agent, on lipid peroxidation, neutrophil infiltration, and antioxidant enzyme activities in a rat model of renal ischemia-reperfusion (I/R) injury. Twenty-eight rats were divided into three groups: sham operation, I/R, and I/R plus erdosteine groups. After the experimental procedure, rats were sacrificed and kidneys were removed and prepared for malondialdehyde (MDA) levels, myeloperoxidase (MPO), xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD) activities. MDA level, MPO and XO activities were significantly increased in the I/R group. On the other hand, SOD and CAT activities were found to be decreased in the I/R group compared to the sham group. Pretreatment with erdosteine significantly diminished tissue MDA level, MPO and XO activities. Our data support a role for erdosteine in attenuation in renal damage after I/R injury of the kidney, in part at least by inhibition of neutrophil sequestration and XO activity.     

The protective effect of aprotinin and alpha-tocopherol on ischemia-reperfusion injury of the rat liver

BACKGROUND: Liver injury caused by ischemia-reperfusion (I/R) processes is a complication of hepatic resection surgery and transplantation, particularly using grafts from marginal donors. Despite improvements in organ preservation and advances in surgical techniques, I/R injury remains a significant clinical problem. In this study, we investigated whether aprotinin provided protection against the adverse effects of I/R injury in liver tissue. METHODS: Forty rats were randomized into four groups (n = 10): group I: (control group) I/R + no medication; group II: sham-operated group + no medication or I/R; group III: I/R + aprotinin; group IV: I/R + alpha-tocopherol. Malondialdehyde (MDA) was measured in the liver tissue and superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as lactate dehydrogenase (LDH) in rat serum. RESULTS: Administration of aprotinin and alpha-tocopherol before I/R resulted in significant reductions of MDA levels compared to the I/R alone group (group I; P = .01 and P < .01, respectively). Administration of aprotinin or alpha-tocopherol prior to I/R resulted in significant increases in SOD and CAT levels compared with the I/R group (P < .05 each). Compared to the I/R group, significant decreases in plasma AST, ALT, and LDH levels were observed both in the aprotinin and in the alpha-tocopherol group (P < .05). Histological evaluation revealed the injury grade to be relatively lower among groups III and IV compared to group I. DISCUSSION: In conclusion, rat hepatic structures in aprotinin and alpha-tocopherol administered groups were well protected. Therefore, aprotinin may provide protection against the adverse effects of I/R injury in liver transplantation.     

Protective effect of rutin on testicular ischemia-reperfusion injury

Purpose

The pathophysiology of testicular torsion-detorsion is an ischemia-reperfusion injury caused by overgeneration of reactive oxygen species (ROS). This study aimed to investigate the effect of rutin, a well-known antioxidant, on testicular ischemia-reperfusion injury.

Methods

Sixty male Sprague-Dawley rats were randomly divided into 3 groups, each containing 20 rats. Rats in the control group underwent a sham operation of the left testis. In the torsion-detorsion group, the left testis was rotated 720° for 2 hours. Rats in the treatment group received the same surgical procedure as the torsion-detorsion group, but rutin was administered intravenously at the time of detorsion. Bilateral orchiectomy was performed on half of the rats in each experimental group at 4 hours after detorsion for measurement of malondialdehyde, an indicator of intratesticular ROS content, and for evaluation of superoxide dismutase and catalase, which are endogenous antioxidant enzymes. Orchiectomy was performed on the remaining rats at 3 months after detorsion for analysis of testicular spermatogenesis.

Results

Unilateral testicular torsion-detorsion caused a significant increase in malondialdehyde level and caused significant decreases in superoxide dismutase, catalase activities, and spermatogenesis in ipsilateral testes. The rats treated with rutin had a significant decrease in malondialdehyde level and had significant increases in superoxide dismutase, catalase activities, and spermatogenesis in ipsilateral testes, compared with torsion-detorsion group.

Conclusions

Rutin protects testes from ischemia-reperfusion injury. The protective effect of rutin may be caused by scavenging ROS by increasing superoxide dismutase and catalase activities.     

舒芬太尼延迟性预处理对心肌缺血再灌注损伤及Caspase-3的影响

目的 探讨舒芬太尼延迟性预处理对大鼠心肌缺血再灌注损伤及Caspase-3表达的影响.方法 健康成年Wistar大鼠90只,随机均分为3组:假手术组(S组)、心肌缺血再灌注组(L/R组)、舒芬太尼组(SF组).每组又按再灌注时间30 min(T1)、60 min(T2)和120 min(T3)分为3个组,每组各10只.缺血再灌注24 h前,S组、I/R组输注生理盐水20ml,SF组输注含舒芬太尼5μg/kg生理盐水20ml.S组仅开胸,分离冠状动脉但不夹闭.I/R组、SF组采用夹闭左冠状动脉前降支40 min后再灌注的方法制备心肌缺血再灌注模型.分别于再灌注30、60、120 min处死实验动物.测定缺血再灌注各时相心肌肌钙蛋白I(cTnI)、Caspase-3含量、凋亡指数(AI),电镜下观察心肌超微结构.结果 缺血再灌注可导致cTnI、Caspase-3、AJ值升高,心肌超微结构发生病理学改变,舒芬太尼延迟性预处理可减弱上述改变(P<0.05).结论 舒芬太尼延迟性预处理可能通过调节Caspase-3表达抑制细胞凋亡,对大鼠缺血再灌注心肌产生保护作用.     

The effect of nitric oxide in testicular ischemia-reperfusion injury

This experiment was carried out to investigate the effect of endogenous nitric oxide (NO) on the ischemia-reperfusion injury of testis.Testicular ischemia was achieved by twisting the right testis and spermatic cord 1080 counter-clockwise for 30 minutes and reperfusion was allowed for 30 minutes after detorsion of 33 rats. Animals were treated with normal saline in controls just before detorsion,NG-nitro-L-arginine methyl ester (L-NAME), and L-arginine (L-arg) in others.The tissue damage was evaluated with light microscopy, malondialdehyde (MDA) level in tissue, and the blood flow measurement using ¹³³xenon (Xe) clearence technique.MDA indicator of reperfusion injury increased 25% after detorsion when only normal saline was given, L-NAME further increased MDA, L-arginin decreased MDA to control level.Conclusion: L-arginin infusion during the detorsion reduced the reperfusion injury of testis and improved the testicular blood flow after the detorsion.     

Comparison of histologic and flow cytometric evaluation of cyclophosphamide-induced testicular damage

This study evaluates the ability of DNA histograms obtained by flow cytometry to detect and quantify reversible alterations in spermatogenesis induced by cyclophosphamide, a known inhibitor of spermatogenesis. Evaluation of per cent of cells in each of the haploid (lc), diploid (2c), and tetraploid peaks (4c) as determined by flow cytometry in treated and control Balb/C mice over a six-week period, and comparison with routine histologic evaluation have led us to conclude that DNA histogram evaluation is a rapid and accurate means of identifying testicular damage and recovery. This technique may be useful in sequential monitoring of the effects of malignancy and/or treatments applied on spermatogenesis in young men.     

The protective effect of acadesine on lung ischemia-reperfusion injury

The purine precursor acadesine is highly effective in preventing ischemia-reperfusion (I-R) injury of the heart and intestine. The aim of this study was to test the effect of acadesine on I-R--induced lung injury. The lobar artery of the left lower lung lobe in intact-chest, spontaneously breathing cats was occluded for 2 h (Group 1, ischemia) and reperfused for 3 h (Group 2, I-R). Animals were subjected to one of the following three protocols: acadesine administered IV 15 min before ischemia (Group 3), 15 min before reperfusion (Group 4), or 30 min after reperfusion (Group 5). Acadesine was administered at an initial dose of 2.5 mg. kg(-1). min(-1) for 5 min, followed by 0.5 mg. kg(-1). min(-1) until the end of reperfusion. Injury was assessed by histologic examination. The right lower lobe served as control. Compared with the right lower lobe, which showed no abnormal findings in any group (percentage of injured alveoli, 2% +/- 1% to 4% +/- 2%), the left lower lung lobe in the I-R group revealed a disrupted alveolar structure with 63% +/- 9% injured alveoli. Ischemia alone did not produce alterations in alveolar structure. Acadesine significantly reduced the number of injured alveoli when given before ischemia (4% +/- 1%) or reperfusion (6% +/- 2%) but not when administered after reperfusion (62% +/- 8%). In conclusion, acadesine, when administered before ischemia or reperfusion, can blunt I-R-induced lung injury. The mechanism underlying the protection remains to be elucidated. IMPLICATIONS: Acadesine reduces ischemia-reperfusion-induced lung injury in spontaneously breathing cats when administered before ischemia or reperfusion, but not after reperfusion.     

The effect of body temperature in a rat model of renal ischemia-reperfusion injury

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is an unavoidable event in renal transplantation; the effects of IRI can be seen in both the acute and long-term function of the transplanted organ. For this reason, research into the pathophysiology of ischemia-reperfusion is at the forefront of transplantation research. Animal models, particularly in the rat, provide a useful research tool in studying the intricacies of IRI and in evaluating new treatments. We describe a model of right nephrectomy and left renal clamping for 45 minutes and demonstrate the effects of temperature variation during the ischemic period. METHODS: Male Sprague-Dawley rats (under isoflurane anesthesia) underwent bilateral flank incision with removal of the right kidney and clamping of the left renal hilum for 45 minutes. The animals were divided into 3 groups (n=6): group 1 had the procedure performed on a heating mat with no temperature control facilities, group 2 used no heating mat, and group 3 used a rectal temperature-controlled homeothermic blanket system (Harvard Medical, United Kingdom). Temperature was taken every 5 minutes throughout the procedure and blood samples were taken on a daily postoperative basis via tail vein venepuncture. RESULTS: The average temperature at the end of the procedure in group 1 was 39.67 degrees C and the creatinine level at day 3 was 574+/-17.84, in group 2 the temperature was 32.6 degrees C and the creatinine level was 115+/-4.06, and in group 3 the temperature was maintained between 36.5 degrees C-37 degrees C and the serum creatinine level was 329+/-19.18. The temperature of the animal during the ischemia phase of IRI significantly affects the severity of injury. Relative hyperthermia resulted in more severe renal injury and unrecoverable acute renal failure, no source of heat led to a relative hypothermia, and reduction of renal injury. Use of the homeothermic heating blanket led to an increase in creatinine level by day 3, indicating a significant ischemic stimulus; however, by day 10 the creatinine level had returned to normal. CONCLUSION: This illustrates the importance of temperature as a variable in animal models of IRI and thus should be clearly stated in all experimental methods to ensure an appropriate ischemic stimulus and for adequate comparisons between various therapeutic interventions.     

肾上腺髓质素对大鼠肺缺血再灌注损伤的保护作用

目的 观察肾上腺髓质素(ADM)在肺缺血再灌注损伤的保护作用.方法 三套管法建立大鼠左肺移植模型,分对照组和静脉ADM给药组(每分钟0.05μ/kg体重),分别进行髓过氧化物酶(MPO)活性测定、移植肺支气管肺泡灌洗液(BAL)中性粒细胞计数、缺血再灌注后血气分析以及移植肺组织湿/干(W/D)重最比测定.结果 再灌注4 h后,对照组的MPO活性(0.45±0.07)显著大于ADM给药组(0.24±0.06),差异有统计学意义(t=2.764,P<0.05).对照组左肺BAL中性粒细胞计数值为(152士23)×105,明显高于ADM给药组的BAL中性粒细胞计数值(87±12)×103,t=2.813,P<0.05.对照组移植肺组织湿/干(W/D)重量比为8.39±0.96,显著高于ADM给药组7.02±0.71(t=3.509,P<0.01).在灌注2 h时,对照组左肺静脉血氧分压为(177.62±23.12)mm Hg(1 mm Hg=0.133 kPa),显著低于ADM给药组(438.50±45.5)mm Hg(t=3.016,P<0.05);再灌注4 h时,对照组左肺静脉血氧分压为(141.75±19.32)him Hg,显著低于ADM给药组427.75±49.98(t=3.248,P<0.05.此外,对照组在再灌注4 h的左肺静脉血氧分压较再灌注2 h时明显降低(t=2.583,P<0.05);而ADM给药组在再灌注2h和4 h时的左肺静脉血氧分压却无显著变化(t=2.134,P>0.05).结论 ADM能够通过抑制移植肺缺血再灌注过程中炎性损伤的机制发挥其器官保护的功能.     

Protective effect of a nuclear factor-kappaB inhibitor on ischemia-reperfusion injury in a rat epigastric flap model

We examined whether nuclear factor-kappa B (NF-kappaB) activation was involved in the ischemia-reperfusion (I/R) injury in a rat skin flap model and whether administration of pyrrolidine dithiocarbamate (PDTC), a NF-kappaB inhibitor, could improve flap viability. Eighty-four Sprague-Dawley rats were divided into control group (n = 28), I/R group (n = 28), and PDTC-treated group (n = 28). An abdominal skin flap (4 x 5 cm) was elevated and subjected to 10 hours of ischemia in both the I/R group and the PDTC-treated group. A bolus of PDTC (300 mg/kg) was infused 5 minutes before reperfusion, followed by a second dose during the first 30 minutes of reperfusion in the PDTC-treated group. Flap tissues were assessed by electrophoretic mobility shift assay at 1, 2, 3, and 6 hours of reperfusion, and myeloperoxidase activity and neutrophil infiltration were assessed at 12 hours of reperfusion. The viability of flaps was assessed 7 days postoperatively. NF-kappaB was activated after reperfusion in the I/R group and displayed peak activity at 1 and 3 hours of reperfusion. In the PDTC-treated group, NF-kappaB activity was significantly reduced at 1, 2, and 6 hours of reperfusion. Myeloperoxidase activity was significantly decreased, and little neutrophil infiltration could be observed. In the PDTC-treated group, the survival of flaps was 86.88 +/- 13.63%, which was significantly greater than the I/R group, in which only 19.20 +/- 7.52% of the flap survived. NF-kappaB is activated during reperfusion in a rat skin flap I/R model. Administration of PDTC can significantly improve flap survival by regulating the early activation of NF-kappaB and suppressing neutrophil infiltration within the flap.     

潘生丁对实验大鼠肝缺血再灌注损伤的影响

目的探讨潘生丁对肝缺血再灌注损伤的保护作用。方法建立大鼠局部肝脏缺血再灌注模型。将24只健康雄性Wistar大鼠随机分为假手术组、缺血再灌注组、潘生丁预处理组,观察各组血浆肝酶及透明质酸(HA)水平变化和肝组织中丙二醛(MDA)、内皮素(ET-1)含量,并行肝组织病理形态学检查。结果与缺血肝组织相比,潘生丁预处理组肝酶的漏出、血浆HA水平及肝组织中MDA、ET-1的含量明显降低(P<0.01)。肝组织病理学损伤亦明显减轻。结论潘生丁预处理可明显改善肝微循环,减轻肝缺血再灌注损伤。药物预处理可为临床提供一种安全有效的预处理方法。