Protective effects of royal jelly on testicular torsion induced ischaemia reperfusion injury in rats

This study was performed to investigate the protective effects of royal jelly (RJ) on a testicular torsion-induced ischaemia/reperfusion (I/R) injury in adult rats. A total of 40 male Wistar rats were divided into four groups, including 10 rats in each group: Group 1 (sham), Group 2 (Control), group 3 (I/R rats treated with 100 mg/kg RJ for 50 days after torsion) and group 4( I/R rats treated with 20 mg/kg vitamin C for 50 days after torsion). Testicular torsion was created by rotating the right testes 720° a clockwise direction for 90 min. The levels of testosterone were measured by ELISA. Pathological evaluation, mean maturity and quality of the seminiferous tubules were used. Results showed that the testicular histopathology standards and testosterone levels changes were statistically significant in groups 3 and 4. The results obtained in this study may suggest that RJ like vitamin C had protective effects on a testicular ischaemia/reperfusion-induced injury in rats.     

The protective effects of nitric oxide on the contralateral testis in prepubertal rats with unilateral testicular torsion

OBJECTIVE: To investigate histological changes in the contralateral testis of rats with unilateral testicular torsion and the protective effects of nitric oxide (NO) on possible damage. MATERIAL AND METHODS: Twenty-eight prepubertal male Sprague-Dawley rats were divided into four equal groups. Group 1 underwent a sham operation of the right testis under general anaesthesia. Group 2 underwent a similar operation but the right testis was rotated 720 degrees clockwise for 6 h, maintained by fixing the testis to the scrotum, and saline infused during the procedure. Group 3 underwent similar torsion but L-arginine methyl ester (a precursor of NO) was infused during the procedure. In Group 4, NG-nitro-L-arginine-methyl ester, a NO synthase inhibitor, was infused separately during the administration of L-arginine methyl ester and torsion. All the left (untwisted) testes were removed from rats 21 days after surgery and evaluated histologically, assessing seminiferous tubule diameter, loss of sperm and spermatids, loss of germ cell layers, disarray of germ cell layers, rupture of tubules, Leydig cell proliferation and reaction in the ruptured tubules, and oedema. RESULTS: There was a significant difference in the indicators of histological damage between groups 2 and 4 and groups 1 and 3, except for the Leydig cell reaction in the ruptured tubules and oedema. The damage was significantly less in group 3 than in groups 2 and 4. CONCLUSION: These results suggest that long-term histopathological changes in the contralateral testes are important after unilateral testicular torsion and that NO has a protective effect on the contralateral testis.     

利多卡因预先给药对肾脏缺血再灌注损伤大鼠肾组织CD44和TNF-α表达的影响

目的 评价利多卡因预先给药对肾脏缺血再灌注损伤大鼠肾组织CD44和TNF-α表达的影响.方法 健康雄性Wistar大鼠36只,体重300～350 g,随机分为3组(n=12):假手术组(S组)、肾脏缺血再灌注组(IR组)和利多卡因预先给药组(L组).采用无创动脉夹夹闭双侧肾动脉60min、恢复灌注4 h,建立大鼠肾脏缺血再灌注模型.L组于夹闭双侧肾动脉前5min时尾静脉注射利多卡因5 mg/kg;IR组于夹闭双侧肾动脉前5 min时尾静脉注射等容量生理盐水;S组不夹闭双侧肾动脉,于分离肾动脉后尾静脉注射等容量生理盐水.再灌注4 h时处死大鼠,取肾组织,光镜下观察病理学结果;采用免疫组化法测定肾组织CD44和TNF-α的表达水平.结果 与S组比较,IR组肾组织CD44和TNF-α的表达上调(P＜0.05),L组肾组织CD44和TNF-α的表达差异无统计学意义(P＞0.05);与IR组比较,L组肾组织CD44和TNF-α的表达下调(P＜0.05),肾组织损伤减轻.结论 利多卡因预先给药减轻大鼠肾脏缺血再灌注损伤与其抑制肾组织CD44和TNF-α的表达有关.     

Protective role of natural antioxidant supplementation on testicular tissue after testicular torsion and detorsion

OBJECTIVES: To investigate the impact of garlic extract (GE), which is known for its antioxidant activity, on a testicular torsion/detorsion model in animals and to help understand how to prevent both ischemic and reperfusion injuries after testicular torsion and detorsion. MATERIAL AND METHODS: Six groups of rats (n=7 in each group) were used. The animals in the control group (Group I) did not receive any treatment. The animals in the sham group (Group II) underwent scrotal incision and testicular fixation only. The animals in Groups III-VI underwent 720 degrees of left testicular torsion for 2 h; subsequent detorsion was performed for 2h in Groups IV and VI only. Animals in Groups V and VI were treated exactly the same as those in Groups III and IV, respectively except that they were pretreated with oral GE for 5 days at a dosage of 5 ml/kg. Both testicles in all rats were removed and tissue malondialdehyde (MDA) levels and enzymatic activities of xanthine oxidase (XO) were studied, in addition to a histological evaluation after hematoxylin-eosin staining. RESULTS: Testicular MDA levels and XO activities were higher in Group III compared to Group II (p<0.05). Pretreatment with GE prevented these increases. Detorsion caused more damage and resulted in a further increase in MDA levels but MDA levels were not increased in animals pretreated with GE. Histologically, torsion caused some separation between germinative cells in the seminiferous tubules, which became much more prominent in Group IV and was attenuated by GE pretreatment. There were no significant changes in any of the above-mentioned enzymatic activities or histopathologic changes in the contralateral testicle in any of the groups. CONCLUSIONS: We believe that both testicular torsion and detorsion result in testicular tissue damage by means of lipid peroxidation, which is evident by an increase in the tissue levels of MDA. Dietary supplementation with GE seems to attenuate the generation of toxic free radicals, as evidenced indirectly by low tissue MDA levels.     

缺血预处理对大鼠移植胰腺缺血再灌注损伤的保护作用及其机制的研究

目的：探讨缺血预处理对大鼠移植胰腺冷缺血再灌注损伤和细胞凋亡的保护作用及其机制。方法：24只糖尿病SD大鼠随机分为缺血再灌注组（I/R组,n=6）和缺血预处理组（IPO组,n=18）,IPO组又根据不同方法分为3个亚组：IPO1组（再灌注30s,缺血30s1次,n=6）、IPO2组（再灌注30s,缺血30s3次,n=6）和IPO3组（再灌注30s,缺血30s6次,n=6）。24只SD大鼠为供体,I/R组和IPO组均行同种胰腺移植。另取6只SD大鼠为对照组。检测各组再灌注前、后血糖及再灌注后2h移植胰腺组织中SOD和MDA含量;TUNEL法观察移植胰腺组织细胞凋亡情况,WesternBlot检测移植胰腺组织Bax和Bcl-2蛋白表达情况。结果：1）再灌注后IPO各组相对于I/R组血糖低（P〈0.05,P〈0.01,P〈0.05）;IPO2组较IPO1组和IPO3组血糖低（P均〈0.05）;2）再灌注后IPO组较I/R组移植胰腺组织中SOD含量高（P均〈0.01）,MDA含量低（P均〈0.01）,IPO2组相对于IPO1组和IPO3组SOD含量高（P均〈0.05）、MDA含量低（P均〈0.05）。3）再灌注后IPO组较I/R组移植胰组织中AI值低（P均〈0.01）,IPO2组相对于IPO1组和IPO3组AI值低（P均〈0.05）;4）I/R组胰组织Bax蛋白高表达,Bcl-2蛋白低表达,IPO各组再灌注后移植胰组织Bax蛋白低表达,Bcl-2蛋白高表达,而IPO2组Bcl-2蛋白表达最高,Bax蛋白表达最低。结论：缺血预处理对大鼠移植胰腺的缺血再灌注损伤具有保护作用,并可以减少移植胰腺缺血再灌注后的细胞凋亡,机制与减少氧自由基、上调Bcl-2蛋白和下调Bax蛋白有关。再灌注30s缺血30s重复3次是最佳的大鼠移植胰缺血预处理诱导办法。     

Protective effect of erythropoietin pretreatment in testicular ischemia-reperfusion injury in rats

Background/Purpose

This study was designed to investigate the effects of recombinant erythropoietin (EPO), a hormone widely used for treatment of uremic anemia, in rats subjected to testicular ischemia and reperfusion (I/R).

Methods

Thirty-five male rats were divided into the following: control, sham operated, ischemia (I), I/R, and I/R + EPO groups. In the I group, 2 hours of left unilateral testicular torsion were performed, and in the I/R and I/R + EPO groups, an additional 2 hours of testicular detorsions were performed. The I/R + EPO group was pretreated intraperitoneally with EPO (500 IU/kg) before reperfusion. Testicular tissue samples were examined for biochemical and histopathologic parameters. Apoptotic cells in all testes were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling technique and caspase 3 immunohistochemistry.

Results

At histopathologic examination, ischemic changes in primary spermatocytes were noted in all torted testes. Cellular damage and apoptosis were more severe in ischemic groups than the EPO-pretreated group. There were statistically significant differences in tissue biochemical parameters in the I and I/R groups compared with the I/R + EPO group.

Conclusions

The results of the present study suggest that EPO exerts protective effects against I/R injury via the modulation of free radical scavenger's activities, which decreases lipid peroxidation levels and attenuation of apoptosis.     

雷公藤内酯醇对大鼠肾缺血再灌注损伤时Toll样受体4表达的影响

目的 观察雷公藤内酯醇(TRI)对大鼠肾缺血再灌注损伤时肾组织中Toll样受体4(TLR4)表达的影响.方法 随机将51只Wistar大鼠分为3组.(1)阴性对照组(n=15):游离双侧肾脏,切除右肾,缝合腹壁.(2)缺血再灌注组(n=18):实验过程与阴性对照组相同,但在切除右肾和游离左肾之后,将左肾动、静脉夹闭45 min,然后开通.(3)TRI处理组(n=18):肾缺血再灌注前3 d经大鼠腹腔注射TRI 0.4 mg/kg,每天1次,连续3 d,其他实验过程与缺血再灌注组相同.肾缺血再灌注1、3、5 d后,分别采用全自动生化分析仪检测血清尿素氮(BUN)和肌酐(Cr)的含量;逆转录聚合酶链反应(RT-PCR)方法检测肾组织中TLR4 mRNA的表达水平;免疫印记法(Western blot)检测肾组织中TLR4表达水平.结果 肾缺血再灌注1、3、5 d后,缺血再灌注组和TRI处理组血清BUN及Cr均明显高于阴性对照组(P＜0.01),肾组织中TLR4 mRNA和TLR4的表达也明显高于阴性对照组(P＜0.05);但与缺血再灌注组比较,TRI处理组血清BUN和Cr明显降低(P＜0.01),肾组织中TLR4 mRNA和TLR4的表达也显著降低(P＜0.05).结论 雷公藤内酯醇可以减轻肾缺血再灌注损伤,其机制可能是通过抑制TLR4的表达而发挥作用的.     

七氟醚延迟预处理对大鼠缺血再灌注心肌ARC表达的影响

目的 评价七氟醚延迟预处理对大鼠缺血再灌注心肌带有Caspase富集功能域的凋亡抑制蛋白(ARC)表达的影响.方法 成年雄性SD大鼠64只,体重270～350 g,采用随机数字表法,将其随机分为4组(n=16):假手术组(S组)、心肌缺血再灌注组(I/R组)、七氟醚+假手术组(S-S组)和七氟醚延迟预处理+心肌缺血再灌注组(S-VR组).S-S组和S-I/R组分别吸入33%氧气和2.5%七氟醚2 h,停止吸入后24 h行假手术或心肌缺血再灌注;I/R组和S-I/R组采用结扎左冠状动脉前降支30 min,再灌注2 h的方法制备心肌缺血再灌注模型.于再灌注2 h时处死8只大鼠,取左心室组织,测定心肌梗死范围及细胞凋亡情况,计算凋亡指数,于缺血前即刻及再灌注2 h时各处死4只大鼠,取左心室组织,测定ARC及Caspase-8的表达水平.结果 与S组比较,I/R组和S-I/R组心肌梗死范围及细胞凋亡指数升高,缺血前即刻S-S组和S-I/R组ARC表达上调,再灌注2 h时I/R组Caspese-8、表达上调(P＜0.05);与I/R组比较,S-I/R组心肌梗死范围和细胞凋亡指数降低,再灌注2 h时S-S组和S-I/R组ARC表达上调,Caspase-8表达下调(P＜0.05).结论 七氟醚延迟预处理可上调心肌ARC表达,减少细胞凋亡的发生,从而减轻大鼠心肌缺血再灌注损伤.

Abstract：

Objective To investigate the effects of sevoflurane delayed preconditioning on caspase recruitment domain (ARC) expression during myocardial ischemia-reperfusion (I/R) in rats. Methods Sixty-four adult male SD rats weighing 270-350 g were randomly divided into 4 groups ( n = 16 each): sham operation (group S); myocardial I/R group; sevoflurane + sham operation group (group S-S) and sevoflurane delayed preconditioning + myocardial I/R group (group S-I/R) . Myocardial I/R was induced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 2 h of reperfusion in groups I/R and S-I/R. Group S-S inhaled 33% oxygen for 2 h, and sham operation was performed 24 h later. Group S-I/R inhaled 2.5% sevoflurane for 2 h, and then myocardial I/R was induced 24 h later. Eight animals were sacrificed at the end of 2 h reperfusion in each group and the hearts removed for determination of myocardial infarct size (IS) as a percentage of area at risk (AAR) by triphenyl tetrazolium chloride staining (IS/AAR) . Myocardial apoptosis was detected using TUNEL and apoptosis index was calculated. Another 4 animals were sacrificed immediately before ischemia and at the end of 2 h reperfusion to determine the expression of ARC and Caspase-8 in myocardium by Western blot. Results Compared with group S, the infarct size and apoptosis index were significantly increased in groups I/R and S-I/R, and ARC expression was up-regulated immediately before ischemia in groups S-S and S-I/R, and Caspase-8 expression was up-regulated at 2 h of reperfusion in group I/R ( P ＜ 0.05) . Compared with group I/R, the infarct size and apoptosis index were significantly decreased in group S-I/R, and ARC expression was up-regulated, while Caspase-8 expression was down-regulated at 2 h of reperfusion in groups S-S and S-I/R ( P ＜ 0.05) . Conclusion Sevoflurane delayed preconditioning can attenuate myocardial I/R injury through up-regulating the ARC expression and decreasing the myocardial apoptosis.     

脂氧素A4对大鼠局灶性脑缺血再灌注损伤时炎性反应的影响

目的 探讨脂氧素A4对大鼠局灶性脑缺血再灌注损伤时炎性反应的影响.方法 雄性健康SD大鼠56只,体重200～250 g,随机分为3组:假手术组(S组,n=8),缺血再灌注组(I/R组,n=24),脂氧素A4组(LXA4组,n=24).采用线栓法阻塞大鼠右侧大脑中动脉制备局灶性脑缺血再灌注模型,LXA4组脑缺血后5 min经侧脑室注射脂氧素A4 0.03 nmol/5 μl,S组和I/R组注射等容量生理盐水,缺血2 h后拔出线栓行再灌注.再灌注24 h时行神经功能缺陷评分,然后断头取脑,光镜下观察病理学,采用比色法检测髓过氧化物酶活性,免疫组织化学方法检测星形胶质细胞和小胶质细胞的活化,ELISA法检测再灌注1、6、12、24和48 h时TNF-α、IL-β、转化生长因子β(TGF-β1)及IL-10的含量.结果 与S组比较,I/R组大鼠神经功能缺陷评分、髓过氧化物酶活性、TNF-α、IL-1β、TGF-β1和IL-10的含量升高,星形胶质细胞和小胶质细胞的活化数目增多(P<0.05);与I/R组比较,LXA4组神经功能缺陷评分、髓过氧化物酶活性、TNF-α和IL-1β含量降低,TGF-β1,和IL-10含量升高,星形胶质细胞和小胶质细胞的活化数目减少(P<0.05).病理结果显示:LXA4组脑缺血再灌注损伤程度较I/R组减轻.结论 脂氧素A4可通过抑制炎性反应减轻大鼠局灶性脑缺血再灌注损伤.     

Nortriptyline protects testes against germ cell apoptosis and oxidative stress induced by testicular ischaemia/reperfusion

We designed this experiment to evaluate the effects of nortriptyline on testicular injury after torsion/detorsion (T/D). Ninety‐six adult Wistar rats were divided into six groups 16 each in control group (Group 1), sham operated (Group 2), T/D + saline (Group 3), and in groups 4–6; were administered 2, 10 and 20 mg kg^?1, i.p. of nortriptyline 30 and 90 min after torsion respectively. Testicular torsion was created by twisting the right testis 720° in clockwise direction for 1 h. In six rats of each group, tissue MDA level and caspase‐3 activity increased and the activities of catalase, superoxide dismutase and glutathione peroxidase decreased in compared with control group 4 h after detorsion (P < 0.001). In six rats of each group 24 h after detorsion, histopathological changes and germ cell apoptosis were significantly deteriorated by measuring mean of seminiferous tubules diameters (MSTD) and TUNEL test. Moreover, 30 days after T/D, sperm concentration and motility were examined in rest of rats. Pre‐ and post‐reperfusion nortriptyline could reduce MDA and caspase‐3 levels and normalise antioxidant enzymes activities, dose dependently. Germ cell apoptosis was significantly decreased, and the MSTD, as well as sperm functions, were significantly improved. Inhibition of mitochondrial permeability transition pore is probably involved in protective effects of nortriptyline against testicular T/D cell damages.     

The Evaluation of Protective Effects of FK-506 on Neural Ischemic-Reperfusion Injury: an Experimental Study

Abstract Objective: In this study, we aimed to delineate the mode of neuroprotective action of FK-506, and demonstrated that FK-506 could decrease oxidative stress and apoptotic cell death in an in vivo rat model of neural ischemia-reperfusion after hemorrhagic shock. Methods: Thirty rats were used as experimental subjects and divided into five equal groups. Group A rats (sham group, n = 6) were anesthetized and craniotomies were performed for collecting brain tissue samples. In group B ischemia-reperfusion (I/R + 1 h, n = 6), group C (I/R + 24 h, n = 6), group D (I/ R + 1 h FK-506, n = 6) and group E (I/R + 24 h FK-506, n = 6), systolic blood pressure of the rats decreased to 40–50% of the normal level via bleeding from the femoral vein. Thus, a hemorrhagic shock and ischemic neural tissue model was formed. The bloodwas retained and given to the remaining animals in groups B, C,Dand E via femoral vein for reperfusion 20 min after the procedure. In group D and E, 1 mg/kg FK-506 in 0.5 ml isotonic solution was administered to the rats 5 min before reperfusion. Group B and D rats were sacrificed after 1 h and group Cand E rats were sacrificed 24 h after reperfusion; the rats were sacrificed via bleeding associated with intracardiac puncture. Craniotomy was also performed in groups B, C, D and E and brain tissue samples were fixed using neutral buffered 10% formaldehyde solution for immunohistopathological examination as in group A. Brain tissue superoxide dismutase (SOD) activities, malondialdehyde (MDA) levels, tissue myeloperoxydase (MPO) activities and apoptotic cell analyses with Apo 2.7 immunohistochemically were also performed in all groups. Results: The result of the study revealed that the SOD activities were lower for groups B (I/R + 1 h) and C (I/ R + 24 h) than for group A (sham group) (p < 0.05). In addition, SOD activities were higher in groups D (I/ R + 1 h FK-506) and E (I/R + 24 h FK-506) than in groups B (I/R + 1 h) and C (I/R + 24 h) (p < 0.05). MDA levels, MPO activities and the number of apoptotic cells were lower in group A (sham group) than in groups B (I/R + 1 h) and C (I/R + 24 h) (p < 0.05). In addition to these MDA levels, MPO activities and the number of apoptotic cells were higher in groups B (I/R + 1 h) and C (I/R + 24 h) as compared to groups D (I/R + 1 h FK-506) and E (I/R + 24 h FK-506) (p < 0.05). Conclusion: The results suggest that the prophylactic use of FK-506 in an in situ ischemic neural tissue may prevent reperfusion injury.     

The role of nitric oxide in testicular ischemia-reperfusion injury

PURPOSE: This study was designed to determine the role of nitric oxide (NO) in the ischemia-reperfusion (I/R) injury process in testes. METHODS: Fifty prepubertal male rats were divided into 5 groups each containing 10 rats. After 4-hour torsion and 4-hour detorsion, bilateral orchiectomies were performed for measurement of tissue malondialdehyde (MDA) level and histopathologic examination. The results were compared statistically. The groups were labeled as group 1, basal values of biochemical parameters in testes; group 2 (control group), torsion plus detorsion; group 3, torsion plus N-monomethyl-L-arginine (L-NMMA) plus detorsion; group 4, torsion plus L-arginine plus detorsion; group 5, sham operation. RESULTS: The highest MDA values were determined in the L-arginin group in ipsilateral testes. Group 3 and group 4 were statistically different from control group. Histological examination showed that specimens from group 4 had a significantly (P < .05) greater histological injury than group 3, and contralateral testes showed normal testicular architecture in all groups. CONCLUSIONS: These results suggest that NO plays an important role in damaging the testis with I/R. Although inhibition of NO synthesis with L-NMMA significantly improves I/R injury in testes, enhancing NO production by providing excess of L-arginine increases such damage. In the early periods of detorsion, there is no damage to contralateral testes after unilateral testicular torsion.     

Pyrrolidine dithiocarbamate prevents 60 minutes of warm mesenteric ischemia/reperfusion injury in rats

BACKGROUND: Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight thiol antioxidant and potent inhibitor of nuclear factor-kappaB (NF-kappaB) activation. It has been shown to attenuate harmful effects of ischemia/reperfusion (I/R) injury in many organs. In recent animal studies, destructive effects of reperfusion injury has been demonstrated. In this study, we aimed to investigate whether PDTC prevents harmful effects of superior mesenteric I/R injury in rats. METHODS: Wistar-albino rats were randomly allocated into the following 4 groups: (1) sham-operated group--these animals underwent laparotomy without I/R injury (group I, n = 12); (2) sham+PDTC group--identical to sham-operated rats except for the administration of PDTC (100 mg/kg intravenous bolus) 30 minutes prior to the commencement of the experimental period (group II, n = 12); (3) I/R group--these animals underwent laparotomy and 60 minutes of ischemia followed by 120 minutes of reperfusion (group III, n = 12); (4) PDTC-treated group (100 mg/kg, intravenously, before the I/R, group IV, n = 12). All animals were killed, and intestinal tissue samples were obtained for investigation of intestinal mucosal injury, myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, glutathione (GSH) levels, and intestinal edema. RESULTS: There was a statistically significant decrease in GSH levels, along with an increase in intestinal mucosal injury scores, MPO activity, MDA levels, and intestinal tissue wet-to-dry weight ratios in group III when compared to groups I, II, and IV (P < .05). However, PDTC treatment led to a statistically significant increase in GSH levels, along with a decrease in intestinal mucosal injury scores, MPO activity, MDA levels, and intestinal tissue wet-to-dry weight ratios in group IV (P < .05). CONCLUSIONS: This study showed that PDTC treatment significantly prevented the reperfusion injury caused by superior mesenteric I/R. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent to use in particular operations where the reperfusion injury occurs.     

The effects of iloprost and vitamin C on kidney as a remote organ after ischemia/reperfusion of lower extremities

BACKGROUND: Abdominal aortic surgery can cause ischemic/reperfusion (I/R) injury in not only the lower extremities, but also in the remote organs and tissues such as lungs, kidneys, heart, and liver during abdominal aortic surgery. It can result in mortality and morbidity because of the remote organ injury in early postoperative period. In this study, we investigate the effects of iloprost and vitamin C on the kidney remote organ damage after I/R following abdominal aortic surgery. MATERIAL AND METHODS: Thirty-four adult male Wistar rats were used and divided into five groups. I/R was studied infrarenally in the abdominal aorta following a median laparotomy. The left kidney was excised immediately following the laparotomy in group I (n = 6, normal group). Group II (n = 6) was the sham group. Group III (n = 6, control group) was subjected to 3 h of ischemia followed by an hour of reperfusion. Group IV (n = 8) was given iloprost 20 ng/kg/min during I/R period before aortic-clamping. Group V (n = 8) was given vitamin C 100 mg/kg during I/R period before aortic-clamping. Arterial blood samples were obtained to determine the levels of blood pH, pO(2) (mmHg), pCO2 (mmHg), HCO(3) (mmol/L), and plasma malondialdehyde (MDA, nmol/mL) at the end of reperfusion period in all groups. The left kidneys were used for remote measurements of tissue MDA (nmol/g.w.t) and scored by histopathological examination for acute inflammation. RESULTS: While the arterial blood pO(2) and HCO(3) levels significantly increased, the plasma and renal parenchymal MDA levels significantly decreased in both group IV and group V when compared to group III (P < 0.05). Histopathological and acute inflammation scores statistically decreased in both group IV and V compared with group III (P < 0.05). Although MDA levels, histopathologic and acute inflammation scores in group V were lower than group IV, the differences were not statistically significant (P > 0.05). CONCLUSION: Both iloprost and vitamin C decreased remote organ damage on the kidney after I/R of lower extremities in the rat model. However, vitamin C is more effective than iloprost in preventing postoperative renal dysfunction.     

Protective effects of Stevia rebaudiana aqueous extract on experimental unilateral testicular ischaemia/reperfusion injury in rats

This project aimed to examine Stevia rebaudiana aqueous extract protective effects on testicular ischaemia/reperfusion injury of rats. Forty rats were randomly divided into five groups: (1) sham group, (2) torsion/detorsion group, (3 and 4) low and high doses treatment groups received S. rebaudiana extract intraperitoneally 30 min before detorsion by 500 and 1,000 mg/kg respectively, and (5) healthy group received the extract by 1,000 mg/kg. In this study, left testes were rotated 2 hr, reperfusion period took long 5 hr, and then orchiectomy was performed. Histopathological and biochemical evaluations of testicular tissue samples were performed. Histopathologically, sham and healthy groups exhibited normal seminiferous tubules. Germinal cell necrosis, interstitial oedema, haemorrhage and congestion were seen in torsion/detorsion group. Testicular tissues of both treatment groups revealed lower histopathological alterations. Significant higher malondialdehyde level was observed in torsion/detorsion group than sham and healthy groups (p < .05). Compared with torsion/detorsion group, S. rebaudiana extract significantly reduced malondialdehyde level in treatment groups (p < .05). Torsion/detorsion group had significantly lower glutathione peroxidase and superoxide dismutase activities than sham and healthy groups, and these parameters showed significant increase in treatment groups compared with torsion/detorsion group (p < .05). The results revealed S. rebaudiana has this potential to protect the testes from ischaemia/reperfusion injury.     

Minocycline attenuates testicular damages in a rat model of ischaemia/reperfusion (I/R) injury

Testicular torsion is a serious urological disease leading to testicular damage. This study aimed to assess the effect of minocycline on testicular ischaemia/reperfusion (I/R) injury caused by testicular torsion/detorsion. Male adult Wistar rats (n = 32) were assigned into four groups of sham, I/R, I/R + minocycline and minocycline. I/R injury was induced by two sets of surgical operations, including the rotation of the left testis (720°, counterclockwise), followed by detorsion after 4 hr. The administration of minocycline was carried out 30 min before detorsion and then continued for 8 weeks. At the end of the 8th week, rats were killed and sampling was done. Johnson's score, the height of seminiferous tubule epithelium, the mean seminiferous tubule diameter, as well as biochemical parameters, SOD, GPx and CAT, were significantly enhanced in the I/R + minocycline group compared with the I/R group. The administration of minocycline led to a marked decrease in expression levels of Caspase-3, Bax, IL-1β and TNF-α genes, and a remarkable increase in expression levels of Bcl-2, 3β-HSD and 17β-HSD3 genes compared with the I/R group. Administration of minocycline could also reduce the rate of germ cell apoptosis (TUNEL staining). Hence, minocycline was useful in the management of testicular torsion/detorsion.     

Microcirculatory effects of experimental acute limb ischaemia-reperfusion.

BACKGROUND: The object of this study was to develop an animal model in which changes in microvascular haemodynamics and leucocyte-vessel wall interactions due to acute limb ischaemia-reperfusion (I/R) can be measured in the skin. Furthermore, it was investigated whether these changes are related to local muscle injury. METHODS: Male Lewis rats were subjected to unilateral limb ischaemia for 1 h (n = 8) or 2 h (n = 8) by cuff inflation, or to a sham protocol (n = 6). Intravital video microscopic measurements of leucocyte-vessel wall interactions, venular diameter, red blood cell velocity and reduced velocity (which is proportional to wall shear rate) were performed in skin venules before ischaemia and at 0.5, 1, 2, 3 and 4 h after the start of reperfusion. Oedema and leucocyte infiltration of ischaemic/reperfused skeletal muscle were quantified histologically. RESULTS: In skin venules, both 1 and 2 h of ischaemia induced a significant increase in leucocyte rolling (six and five times baseline, respectively; P < 0.05) and adherence during reperfusion (eight and four times baseline; P < 0.05). No significant increase in muscular leucocyte infiltration was detected. After an initial hyperaemic response of 180 per cent of baseline values (P < 0.05), blood flow decreased to about 60 per cent after 4 h of reperfusion in skin venules of both experimental groups. I/R induced tibial muscle oedema, the severity of which depended on the ischaemic interval (wet to dry ratio: control, 4.0; 1 h, 4.5 (P not significant); 2 h, 5.8 (P < 0.05)). CONCLUSION: A non-invasive animal model was developed that enables investigation of the consequences of acute limb I/R.     

Pioglitazone Attenuates Ischemia/Reperfusion–Induced Liver Injury in Rats

Introduction

Hepatic ischemia/reperfusion (I/R) injury leads to free radical generation and acute inflammatory responses that cause liver damage, an important problem for liver transplantation. Pioglitazone is known to protect I/R injury in various tissues; however, the mechanism of cytoprotection is not well understood. This study investigated the effects of pioglitazone administration in a warm hepatic I/R model on tumor necrosis factor (TNF)-α level, tissue injury, and antioxidant enzyme activity.

Materials and Methods

Eighty wistar strain rats were divided into 4 groups (n = 20): Group 1 sham hosts; Group 2 hepatic I/R; Group 3 hepatic I/R + pioglitazone (10 mg/kg); and Group 4 hepatic I/R + vehicle. Rat livers were subjected to 30 minutes of ischemia followed by 6 hours of reperfusion. After reperfusion rats were humanely killed to obtain liver tissue to study glutathione peroxidase (GPx), superoxide dysmutase (SOD), malondialdehyde (MDA) levels and for histopathologic assessment. TNF-α, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured in serum.

Results

Pioglitazone pretreatment significantly reduced liver enzyme content (ALT, 176.80 ± 13.75 vs 235.28 ± 31.92 and AST, 748.20 ± 79.29 vs 944.85 ± 101.87) and TNF-α level (9:8.60 ± 8.67 vs 138.28 ± 9.99) after I/R compared with the control group. MDA level (3.02 ± 0.37 vs 4.36 ± 0.38) and hepatocytic degeneration were reduced in the pioglitazone-treated group. GPx (2.40 ± 0.25 vs 1.36 ± 0.31) and SOD activity (2.22 ± 0.30 vs 1.40 ± 0.35) were significantly higher in the pioglitazone-treated group compared with the control group.

Conclusion

The present study showed that pioglitazone administration improved hepatic I/R injury that was associated with enhanced antioxidant enzyme activities and suppression of TNF-α, ALT, and AST levels. Because peroxisome proliferator-activated receptor-γ agonists are widely used to treat diabetic patients, it may be relatively easy to expand their clinical indication. However, further investigations will be required to delineate protective mechanisms by which pioglitazone attenuates hepatic tissue injury after I/R.     

Activated protein C attenuates intestinal reperfusion-induced acute lung injury: an experimental study in a rat model

BACKGROUND: Activated protein C (APC) is a serine protease with anticoagulant and anti-inflammatory activities. APC has been shown to attenuate local deleterious effects of ischemia/reperfusion (I/R) injury in many organs. We aimed to investigate the effects of APC on lung reperfusion injury induced by superior mesenteric occlusion. METHODS: Male Wistar-Albino rats were allocated into 4 groups: (1) sham-operated group, laparotomy without I/R injury (n = 12); (2) sham + APC group, identical to group 1 except for APC treatment (n = 12); (3) intestinal I/R group, 60 minutes of ischemia followed by 3 hours of reperfusion (n = 12); and (4) I/R + APC-treated group, 100 microg/kg injection of APC intravenously, 15 minutes before reperfusion (n = 12). Evans blue dye was injected into half of the rats in all groups. We assessed the degree of pulmonary tissue injury by measuring activities of oxidative and antioxidative enzymes, as well as nitrate (NO(3)(-))/nitrite (NO(2)(-)) levels, biochemically. We evaluated acute lung injury (ALI) by establishing pulmonary neutrophil sequestration and ALI scoring histopathologically. Pulmonary edema was estimated by using Evans blue dye extravasation and wet/dry ratios. The plasma levels of proinflammatory cytokines and D-dimer were measured. RESULTS: APC treatment significantly reduced activities of oxidative enzymes and nitrate/nitrite levels in the lung tissues, and plasma levels of proinflammatory cytokines and D-dimer, and also significantly increased activities of antioxidative enzymes (P < .05). Pulmonary neutrophil sequestration and ALI scores were decreased significantly with APC administration (P < .05). In addition, APC treatment significantly alleviated pulmonary edema (P < .05). CONCLUSIONS: This study clearly showed that APC treatment significantly attenuated the lung reperfusion injury. Further clinical studies are required to clarify whether APC has a useful role in the reperfusion injury during particular surgeries in which I/R-induced organ injury occurs.     

七氟醚预先给药对大鼠肾脏缺血再灌注时细胞凋亡的影响

目的 探讨七氟醚预先给药对大鼠肾脏缺血再灌注时细胞凋亡的影响.方法 健康清洁级雄性SD大鼠30只,体重220～260 g,采用随机数字表法,将大鼠随机分为3组(n=10):对照组(C组)、缺血再灌注组(I/R组)、七氟醚组(S组).I/R组和S组采用夹闭左肾蒂45 min后恢复再灌注的方法 建立肾脏缺血再灌注模型,C组腹部正中切口,右肾切除,左肾蒂游离后,缝合腹腔;S组模型制备前30 min开始吸入2.2%七氟醚和氧气的混合气体至再灌注3 h.于再灌注3 h时采集下腔静脉血样5 ml,测定血清尿素氮(BUN)、肌酐(Cr)浓度,然后取肾组织,光镜下观察肾组织病理学结果,TUNEL法检测细胞凋亡,计算细胞凋亡指数,采用RT-PCR和Western blot法测定血红素氧合酶-1(HO-1)mRNA及蛋白表达水平.结果 与C组比较,I/R组和S组血清BUN、Cr浓度、肾脏近曲小管坏死程度、细胞凋亡指数升高,HO-1 mRNA和蛋白表达上调(P＜0.05);与I/R组比较,S组血清BUN、Cr浓度、细胞凋亡指数、肾脏近曲小管坏死程度降低,HO-1 mRNA表达上调(P＜0.05).结论 七氟醚预先给药可通过抑制细胞凋亡而减轻大鼠肾脏缺血再灌注损伤,其抑制细胞凋亡作用可能与HO-1 mRNA表达上调有关.

Abstract：

Objective To investigate the effects of sevoflurane pretreatment on renal ischemia-reperfusion (I/R)-induced apoptosis in kidney in rats. Methods Thirty pathogen-free male SD rats weighing 220-260 g were randomized into 3 groups (n=10 each):group control (group C);group I/R and group sevoflurane(group S). Renal I/R was induced by clamping the left renal pedicle for 45 min in I/R and S groups. In group S inhalation of 2.2% sevoflurane in O2 was started at 30 min before operation and maintained throughout the experiment.Venous blood samples were taken at 3 h of reperfusion for determination of serum BUN and Cr concentrations. The animals were then sacrificed and the left kidneys were removed for microscopic examination, detection of apoptosis(by TUNEL)and determination of heme oxygenase-1(HO-1) mRNA and protein expression (by RT-PCR and Western blot).Results Renal I/R significantly increased serum BUN and Cr concentrations, apoptotic index(percentage of apoptotic cells) and the severity of necrosis of renal proximal convoluted tubules (0=normal,4=necrosis of whole segment of proximal convoluted tubules).Sevoflurane inhalation attenuated the I/R-induced changes mentioned above.HO-1 mRNA and protein expression was up-regulated by I/R and HO-1 mRNA expression was further up-regulated by sevoflurane inhalation.Conclusion Sevoflurane pretreatment can protect kidney against I/R injury by attenuating cell apoptosis.Up-regulation of HO-1 mRNA expression may be involved in the mechanism.