不同强度电针刺激对脑缺血再灌注大鼠脑能量代谢的影响

目的 探讨不同强度电针刺激对脑缺血再灌注大鼠脑能量代谢的影响.方法清洁级雄性SD大鼠40只,体重200～230 g,采用随机数字表法,将大鼠随机分为5组(n=8):假手术组(S组)、脑缺血再灌注组(I/R组)、脑缺血再灌注+5 mA电针组(I/R+E1组)、脑缺血再灌注+3 mA电针组(I/R+E2组)和脑缺血再灌注+1 mA电针组(I/R+E3组).采用四血管阻断法制备脑缺血再灌注模型.I/R+E1组、I/R+E2组和I/R+E3组分别于模型制备后1、12 h实施电针刺激,20 min/次,电流强度分别为5、3和1 mA.再灌注24 h时,测定脑组织琥珀酸脱氢酶(SDH)、LDH和Na+-K+-ATP酶的活性.结果 与S组比较,I/R组脑组织LDH活性升高,Na+-K+-ATP酶活性降低(P＜0.05),SDH活性差异无统计学意义(P＞0.05),I/R+E1组SDH活性升高(P＜0.05);与I/R组比较,I/R+E1组脑组织LDH活性降低,SDH和Na+-K+-ATP酶活性升高,I/R+E2组和I/R+E3组LDH活性降低(P＜0.05或0.01),SDH和Na+-K+-ATP酶活性差异无统计学意义(P＞0.05);与I/R+E1组比较,I/R+E3组脑组织SDH活性降低(P＜0.05),I/R+E2组差异无统计学意义(P＞0.05);与I/R+E2组比较,I/R+E3组脑组织SDH活性降低(P＜0.05).结论 电针刺激可改善大鼠脑缺血再灌注时的脑能量代谢,且与刺激强度有关,该作用可能是其减轻脑缺血再灌注损伤的机制.

Abstract：

Objective To investigate the effects of electroacupuncture (EA) of different intensities on cerebral energy metabolism in a rat model of global cerebral ischemia-reperfusion (I/R) . Methods Forty male SD rats weighing 200-230 g were randomized into 5 groups ( n = 8 each) : group A sham operation; group B global cerebral I/R and C, D, E groups cerebral I/R+ 5, 3, 1 mA EA. Global cerebral I/R was induced by 4-vessel occlusion technique. Bilateral vertebral arteries were permanently occluded by cauterization.Bilateral common carotid arteries were clamped. When the bilateral pupils were completely dilated, the arteries were unclamped. Baihui,Mingmen and Zusanli were electrically stimulated with 5,3,1 mA (30-50 Hz) for 20 min at 1 h of reperfusion in C, D, E groups. The EA was repeated at 12 h of reperfusion. The animals were sacrificed at 24 h of reperfusion.The activities of Na+ -K+ -ATPase, succinodehydrogenase (SDH) and lactic dehydrogenase(LDH) in brain tissue were measured.Results Cerebral I/R significantly increased LDH activity and decreased Na+ -K+ -ATPase activity in group B as compared with group A. EA with 5 mA significantly decreased LDH activity and increased SDH and Na+ -K+ -ATPase activities in group C compared with group B. Conclusion EA can improve the cerebral energy metabolism in a rat model of global cerebral I/R and it is related to the intensity, which may be the mechanism by which EA reduces the global cerebral I/R injury.     

Effect of FK506 Ointment (Protopic) on Rat Skin Allograft Model

Objective

FK-506 (tacrolimus) is a well known immunosuppressive agent used to prevent allograft rejection. The need for chronic allograft immunosuppression and the consequent harmful systemic effects preclude the use of tissue allograft as a routine surgical reconstructive option. This study assessed the effects of FK-506 ointment (Protopic) therapy versus subcutaneous injection of FK-506 (Prograf) on rat skin graft model.

Methods

Donor Wistar rat dorsal skin was grafted to recipient Sprague-Dawley rats. Animals groups were divided into 2 groups: Group I was treated with intravenous injection of FK-506, and group II was treated with FK-506 ointment for 2 weeks after surgery. Graft appearance challenges were assessed.

Results

FK506 ointment could prolong the median allograft survival time (16.7 days) compared with group I (15.8). Hematoxylin-eosin staining performed on the allo-skin biopsy samples obtained from both group I and II animals at 2 weeks after graft revealed moderate degree of skin rejection accompanied by mixed lymphocyte infiltration. Tacrolimus mean blood levels were much lower in group II (<0.2 ng/mL) than in group I (0.45 ng/mL)

Conclusions

Immunosuppressive FK506 ointment therapy has similar effect to intravenous injection and it could be a useful therapy in the prevention of skin allograft rejection.     

Protective effects of immunophilin ligands on testicular torsion/detorsion damage in rats

Objectives  The purpose was to investigate the role of immunophilin ligands in ischemia/reperfusion (I/R)-induced germ cell apoptosis in the rat. Materials and methods  Sprague–Dawley rats were divided into five groups with ten animals in each. In animals undergoing torsion/detorsion, right testes were rotated 720o for 1 h. A baseline group was for basal normal values. The sham-operated group served as a control group. The TD group underwent torsion/detorsion surgery alone; the cyclosporine-A group (TD-CsA) received intravenous cyclosporine injection (5 mg/kg) at the time of detorsion, and the FK-506 group (TD-FK) received intravenous FK-506 (3.5 mg/kg) at the time of detorsion. For measurement of lipid peroxidation and antioxidant enzyme activities, the right testes of five animals in each group were excised after 4-h reperfusion. Germ cell apoptosis indices were determined 24 h following detorsion in the right testes of the remaining five animals in each group. Results  Malondialdehyde (MDA) levels in the TD group were significantly higher compared to control and baseline groups. Moreover, testicular MDA values in TD-CsA and TD-FK groups were significantly lower than in TD. There were also significant decreases in catalase and superxide dismutase activities in the TD group compared to control and baseline groups. These values in TD-CsA and TD-FK groups were significantly higher than in TD. The mean germ cell apoptosis scores were significantly higher in TD animals compared to control and baseline groups; however, CsA and FK-506 treatment significantly reduced the apoptosis compared with the TD group. Conclusion  We have shown that administration of immunophilin ligands in testicular torsion decreases ischemia/reperfusion (I/R) cellular damage. The results of biochemical studies suggest that reduction of oxidative stress along with attenuated neutrophil accumulation by immunophilin ligands may have a major role in their cytoprotective effects.     

Transplantation of newborn esophagus: an experimental study

PURPOSE: The aim of this study was to see if allogeneic transplantation (Tx) of newborn esophagus can create viable esophageal tissue that may be used for treating long gap esophageal atresia. METHODS: Specimens of thoracic esophagus from newborn Brown-Norway rats, each were transplanted into a pouch created in the distal omentum of 5-week-old Lewis rats. In group I no immunosuppressant was used. FK-506 was used in group II (0.2 mg/kg), group III (0.6 mg/kg), and group IV (1.2 mg/kg) until a predetermined day of graft harvesting (1, 2, 3, 4, 5, 6, and 8 weeks after Tx). FK-506 was used for only 2 weeks in group V (0.6 mg/kg), and group VI (1.2mg/kg), and transplanted esophageal grafts were harvested 1, 2, 3, and 4 weeks after cessation of 2 weeks course FK-506. Syngeneic esophagus transplants were used as controls. All grafts were examined by H&E staining to assess graft viability and degree of rejection. RESULTS: Each successfully transplanted esophagus appeared macroscopically as a tube like mass. Each graft could be mobilized to the thoracic cavity, because of the long omental pedicle. Graft survival in the control group was 100%. Rejection was observed in all grafts from groups I, II, V, and VI. In contrast, grafts from groups III and IV showed only minimal or no rejection. There was no evidence of side effects of FK-506 in rats in groups III and IV, except significantly slower weight gain compared with controls (P <.05). CONCLUSIONS: FK-506 successfully prevented rejection, although immunologic tolerance was not achieved. These observations suggest that the authors' procedure has the potential to produce viable esophageal tissue that could be a new option for treating long gap esophageal atresia.     

Immunosuppressive activity, lymphocyte subset analysis, and acute toxicity of FK-506 in the rat. A comparative and combination study with cyclosporine

The immunosuppressive and toxic properties of the recently discovered macrolide antibiotic FK506 were examined in comparison and in conjunction with cyclosporine administration in the rat. Male Sprague-Dawley rats were immunized systemically with sheep erythrocytes and received, from the same time, either FK506 (1 mg/kg/day) intramuscularly or CsA (25 mg/kg/day) by gavage, or both drugs in combination. Seven days after immunization, the splenic plaque-forming cell response and circulating antibody titers were reduced greater than 90% in animals receiving either FK506 or CsA and in the drug combination group. These immunosuppressive effects of FK506 and CsA were accompanied by significant increases in the incidences of splenic OX-8+ cells and by corresponding reductions in the W3/25+:OX-8+ ratio. No further changes in T cell populations were observed in animals given both drugs. A progressive monocytosis was found in response to CsA, but not in FK506-treated rats. Increases in plasma urea were observed in FK-506 and drug-combination or CsA-treated rats on day 7, whereas creatinine levels were raised only in the FK-506 groups. Elevated bilirubin levels and alterations in liver enzyme activities were observed in CsA-treated rats by day 4, whereas FK-506 alone produced no similar effects. CsA-treated rats also exhibited elevated blood and urinary glucose levels from day 4. No biochemical evidence of additive drug toxicity was detected. The only histological abnormalities observed were thymic medullary atrophy in all drug-treated animals, together with very minor reductions in bone marrow cellularity in a proportion of those rats given FK-506. These findings show that, at the dosage selected, the powerful immunosuppressive activities of FK-506 were associated with little evidence of acute toxicity and with no indications of additive toxicity with CsA.     

IL-17A对脂多糖致老年大鼠早期中枢炎症和场景性恐惧实验的作用

目的探讨IL-17A对脂多糖(LPS)致老年大鼠早期中枢炎症和恐惧实验的影响。方法雄性SD大鼠70只,18月龄,首先取30只大鼠随机均分为五组:腹腔注射生理盐水(生理盐水组,A组)、腹腔注射LPS 500μg/kg 6h组(B组)、12h组(C组)、24h组(D组)、48h组(E组)。检测LPS注射后各组大鼠海马IL-17A的表达。随后,将剩余40只大鼠随机均分为四组:空白对照组(O组)、IL-17A抗体组(P组)、LPS腹腔注射组(Q组)、IL-17A抗体+LPS腹腔注射组(R组)。P组和R组大鼠侧脑室给予IL-17A抗体3μl(200μg/μl),O组和Q组给予同体积生理盐水;30min后,Q组和R组大鼠腹腔注射LPS(500μg/kg),O组和P组给予同体积生理盐水,24h后各组行场景性恐惧实验,记录四组大鼠的僵直时间,检测海马TNF-α和IL-6水平及CA1区Iba1阳性细胞的表达。结果 B、C和D组大鼠海马中IL-17A的表达明显高于A组(P0.01),E与A组IL-17A的表达差异无统计学意义;Q组和R组大鼠僵直反应时间明显短于O组(P0.05或P0.01),R组大鼠僵直反应时间明显长于Q组(P0.01);Q组和R组大鼠海马TNF-α和IL-6的水平明显高于O组(P0.01),R组大鼠海马TNF-α和IL-6水平明显低于Q组(P0.01);Q组和R组大鼠海马CA1区Iba1阳性细胞数目明显多于O组,R组大鼠海马CA1区Iba1阳性细胞数目明显少于Q组(P0.05)。结论 IL-17A参与LPS引起的老年大鼠早期中枢炎症因子TNF-α和IL-6的表达、小胶质细胞的活化以及场景性恐惧实验的僵直时间改变。     

雌激素对大鼠肝切除肝缺血再灌注损伤中核因子-κB/IκB传导通路的影响及保护作用

目的 观察雌激素对大鼠肝切除肝缺血再灌注损伤中核因子-κB(NF-κB)/抑制蛋白(IκB)传导通路影响.方法 制作肝切除肝缺血再灌注损伤动物模型,雄性SD大鼠随机分为3组:假手术组(Sham组);肝切除肝缺血再灌注组(I/R组);肝切除肝缺血再灌注+雌激素组(I/R+ E2 组).分别在缺血再灌注后1、3、6h光镜下观察肝组织病理学改变,检测血清天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的水平和肝组织丙二醛(MDA)的含量及超氧化物岐化酶(SOD)的活性,免疫组织化学法测定肝组织NF-κB的表达,Western blot检测NF-κB抑制蛋白(IκB-α)和细胞间黏附分子-1(ICAM-1)表达,流式细胞仪检测细胞凋亡率.结果 再灌注后I/R组在各时相血清ALT、AST均显著高于I/R +E2组,并于6h达到峰值(P＜0.05).与I/R+E2组和Sham比较,I/R组肝细胞凋亡率显著升高(P＜0.01);肝组织中IκB-α表达降低,而NF-κB表达增高(P＜0.05);ICAM-1 和MDA的结果变化和NF-κB表达水平变化类似,SOD呈相反变化.在光镜下观察,I/R组肝小叶结构紊乱,肝窦淤血,肝细胞水肿变性,肝细胞片状坏死,在Sham组和I/R +E2组上述病理学变化明显改善.结论 雌激素对肝切除肝脏缺血再灌注损伤有显著保护作用,其作用机制可能与雌激素影响NF-κB/IκB传导通路、减轻脂质过氧化反应、减少炎症介质释放及抑制细胞凋亡有关.     

不同时间的缺血预处理对肝硬化大鼠缺血再灌注损伤的保护作用

目的 探讨缺血预处理(IPC)对肝硬化大鼠缺血再灌注损伤(I/R)的保护作用,并寻找对肝硬化I/R保护作用的最佳有效时间窗和理想方案.方法 通过构建正常大鼠及肝硬化大鼠模型,以正常肝脏I/R(A组)和正常肝脏10-10 min-IPC方案(B组)为对照组,肝硬化组则分别施行单纯I/R(C组)、5-10 min(D组)、8-10min(E组)、10-10 min(F组)及15-10 min(G组)的IPC方案,每组18只,分别在术后1 h、4 h及24 h三个时间点采静脉血,检测血清ALT、AST、LDH及肝组织中MDA、MPO、NO、SOD水平,评价肝功能及肝脏组织炎性浸润及抗损伤程度.结果 肝脏缺血30 min后肝脏功能受损明显,表现为各组的ALT、AST、LDH水平升高,尤以再灌注4 h时显著(P<0.05),但经过缺血预处理后,各IPC组中的NO、MDA、MPO及SOD水平亦显著高于其对应的I/R组,以E组的差别有显著意义(P<0.05).结论 10-10 min的IPC方案对于正常肝脏I/R确有保护作用,而8-10 min的IPC方案能最有效地启动对肝硬化大鼠肝脏I/R的保护作用.     

Selenium has a protective effect on ischemia/reperfusion injury in a rat ovary model: biochemical and histopathologic evaluation

Background/PurposeThe aim of the study was to evaluate the effects of selenium (Se) on ischemia/reperfusion (I/R) injury in rat ovaries.MethodsThirty-five female Sprague-Dawley rats were randomly divided into 5 groups (n = 7): sham (S), I/R1, I/R2, Se1, and Se2. In the I/R1 and Se1 groups, 4 hours of ischemia was followed by 6 hours of reperfusion, and in the I/R2 and Se2 groups, 4 hours of ischemia was followed by 12 hours of reperfusion. In the Se groups, 30 minutes before reperfusion, a single dose of 0.2 mg/kg Se was administered intraperitoneally. The ovarian tissue levels of malondialdehyde (MDA) and nitric oxide (NO), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured biochemically. Tissue damage to ovarian tissue was scored by histopathologic examination.ResultsThe I/R groups had significantly higher MDA levels and lower CAT, SOD, and GPx activities than the sham group (P < .05). Although NO levels were significantly higher in the I/R1 group than in the sham group (P < .05), the NO levels in the I/R2 and sham groups were similar. Selenium pretreatment significantly lowered tissue MDA and NO levels and increased tissue SOD and GPx activities in the Se groups, compared with those in the I/R groups (P < .05). Catalase activities were significantly higher in the Se2 group than in the I/R2 group (P < .05). Catalase activities were higher in the Se1 group than in the I/R1 group, but the difference was not statistically significant. Treatment with Se significantly decreased the ovarian tissue damage scores in the Se2 group compared with those in the I/R2 group (P < .05).ConclusionSelenium is effective in preventing tissue damage induced by I/R in rat ovaries.     

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.     

基于TNFR/RIPK1通路探索紫草素对大鼠脊髓损伤的作用及机制

目的:初步探讨紫草素对大鼠急性脊髓损伤(spinal cord injury,SCI)后神经功能恢复的影响及作用机制。方法:将96只Sprague-Dawley(SD)雄性大鼠分为4组:假手术组,即A组;假手术+紫草素组,即B组;脊髓损伤+二甲基亚砜(dimethyl sulfoxide,DMSO)组,即C组;脊髓损伤+紫草素组,即D组;每组24只。C、D组采用钳夹法制作大鼠急性SCI 模型。所有大鼠硬膜下置管,A 组不给药,B组和D组造模后30 min 经导管注射紫草素100 mg·kg^-1,C组注射等量 DMSO,每日1次,至取材时间点。各组分别于造模后6、12 h和3 d 每组取8只大鼠,行 Basso-Beattie-Bresnahan(BBB)评分及造模后1、3、7、14、21 d行斜板实验,再处死动物取脊髓组织。造模后1 h 每组大鼠腹腔注射碘化丙啶(propidine iodide,PI)1 mg·kg^-1,术后24 h取材检测脊髓组织 PI 红染细胞数;24 h 时取材采用苏木素-伊红(haematoxylin eosin,HE)染色观察脊髓损伤情况,尼氏(Nissl)染色观察神经元存活数量,使用Western-blot技术检测 B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)蛋白及凋亡相关蛋白受体相互作用蛋白激酶1(receptor-interacting protein kinase 1,RIPK1)的表达水平。结果:造模后A组和B组各时间点的 BBB 评分均正常,C、D组各时间点均低于A、B组,D组造模后12 h和3 d的 BBB 评分高于同时间点C组(P<0.05)。造模后12 h,D组PI 红染细胞较C 组明显减少,神经元崩解减轻(P<0.05)。造模后24 h,A 组和 B 组脊髓组织 HE 和 Nissl 染色正常,D 组脊髓组织损伤程度和存活神经元数量均优于 C 组(P<0.05)。Bcl-2、RIPK1蛋白在A 组、B 组表达很低; RIPK1 在C组表达明显增高,在D组表达明显下降,差异有统计学意义(P<0.05);Bcl-2蛋白在D 组表达高于C 组(P<0.05)。结论:紫草素可减轻大鼠急性SCI后的病理变化,改善行为学评分,促进脊髓神经功能恢复。其具体机制可能与抑制TNFR/RIPK1信号通路介导的坏死性凋亡有关。     

WOFIE augments the immunosuppressive potency of FK-506

Bidirectional recognition of donor- and recipient-derived immunocompetent cells has been proven to play a pivotal role for the induction of long-term unresponsiveness to allogeneic grafts. This study investigated the fate of heterotopic heart grafts with respect to the timing of subtherapeutic doses of FK-506 and with respect to the time point and type of donor antigen application, leaving space for mutual adaptation of alloreactive lymphocytes, designated as the 'WOFIE-concept' (window of opportunity for immunological engagement), originally described by R Calne. METHODS: Heterotropic heart transplantation was performed using male DA (RT1.a) donor and LEW (RT1.1) recipient rats in the following groups (n = 6). FK-506 was applied intramuscularly (i.m.) using doses of 2 mg/kg x body weight per day. Donor antigen application was performed either by DA blood transfusion, 2 ml intravenously (i.v.), or by i.v. transfusion of 5 x 10(7) DA splenocytes. (i) LEW --> LEW, untreated; (ii) DA --> LEW, untreated; (iii) DA --> LEW, FK-506 days 0, 4-7; (iv) DA --> LEW, FK-506 as group (iii) plus 2 ml of DA blood 6 h post-Tx; (v) same as group (iv) but DA blood transfusion 24 h post-Tx; (vi) DA --> LEW, FK-506 as group (iii) plus DA splenocytes 6 h post-Tx; (vii) same as group (vi) but DA splenocyte transfusion 24 h post-Tx; (viii) DA --> LEW, FK-506 days 0-4 and (ix) DA --> LEW, FK-506 as group (viii) plus DA blood 6 h post-Tx. Immunohistochemical stainings (APAAP-method) of the allografts and flow cytometric analysis of recipient spleens were performed electively 3, 7 and 14 days after organ reperfusion. RESULTS: The mean graft survival differed significantly between groups and comprised (mean +/- SD days): (i) >100, (ii) 6.5 +/- 1.0, (iii) 31.6 +/- 12.1, (iv) 44.8 +/- 10.1, (v) 29.8 +/- 14.2, (vi) 27.2 +/- 4.7, (vii) 14.6 +/- 4.2, 17.5 +/- 4.2, (viii) 17.5 +/- 4.2 and (ix) 18.8 +/- 2.8 days. Prolongation of graft survival and long-term unresponsiveness (group iv) revealed a substantially different pattern of graft infiltration. CONCLUSIONS: Effective treatment with unspecific immunosuppressants like FK-506 can be substantially improved if (i) mutual antigen recognition between donor and recipient immunocompetent cells is warranted, (ii) donor-derived blood-borne antigens are given immediately after graft reperfusion, and (iii) the type of inoculated donor antigen has a strong impact on graft survival as splenocytes which contain a large population of professional antigen-presenting cells failed to prolong graft survival after interrupted FK-506 treatment.     

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.     

The protective effects of 17beta-estradiol on hepatic ischemia-reperfusion injury in rat model, associated with regulation of heat-shock protein expression

BACKGROUND: Ischemia-reperfusion (I/R) injury, which was commonly seen in the field of hepatic surgical intervention, impaired liver regeneration and predisposed to liver failure. Previous studies have shown gender dimorphic response of the liver for various hepatic stresses including I/R injury, hemorrhagic shock-resuscitation, liver cirrhosis, endotoxemia, and chronic alcoholic consumption, and demonstrated gender dimorphism in hepatocellular dysfunction after experimental trauma and hemorrhage. The objective of this study was to examine the hypothesis that the protective effects of 17beta-estradiol (E2) in hepatic I/R injury were associated with increasing heat-shock protein 70 expression. MATERIALS AND METHODS: Sprague-Dawley male and female rats were randomly divided into male and female sham, I/R, and E2 + I/R groups. The model of reduced-size liver ischemia and reperfusion was used. Except for the sham-operated groups, all rats were subjected to 70% liver ischemia for 45 min followed by resection of the remaining 30% nonischemic lobes and reperfusion of ischemic tissue. For each group, five rats were used to investigate the survival during a week after operation; blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase, aspartate aminotransferase, liver tissue NO(2)(-) + NO(3)(-), malondialdehyde content, superoxide dismutase, nitric oxide synthase, and myeloperoxidase activity, Hsp70 expression, and apoptosis ratio. RESULTS: Compared with I/R groups, male and female E2 + I/R groups showed less I/R-induced injury, and SOD and eNOS activity and Hsp70 expression were increased significantly (P < 0.01). A higher rate of apoptosis was observed in the I/R group versus the E2 + I/R group, a significant increase of MDA, NO(2)(-) + NO(3)(-), and MPO of liver tissues and serum transaminase were also observed in the I/R group versus the E2 + I/R group. The survival rate was significantly higher in the male E2 + I/R group than in the male I/R group. CONCLUSION: E2 pretreatment had protective effects on liver in hepatic I/R injury. The mechanism of this protection might be related to overexpression of Hsp70.     

右美托咪啶后处理对大鼠离体心脏缺血再灌注时线粒体损伤的影响

目的 探讨右美托咪啶后处理对大鼠离体心脏缺血再灌注时线粒体损伤的影响.方法 健康雌性Wistar大鼠,体重220～250 g,成功制备Langendorff离体灌注模型的40个心脏随机分为5组(n=8):缺血再灌注组(A组)、右美托咪啶10 nmol/L组(B组)、右美托咪啶100 nmol/L组(C组)、线粒体通透性转换孔开放剂苍术苷组(D组)及右美托咪啶联合苍术苷组(E组).离体心脏经K-H液平衡灌注20 min后,采用全心停灌40 min再灌注60 min的方法制备离体心脏缺血再灌注模型.于再灌注即刻B组、C组、D组和E组分别灌注含10 nmol/L右美托咪啶、100 nmol/L右美托咪啶、20μmol/L苍术苷、100 nmol/L右美托咪啶和20 μmol/L苍术苷的K-H液10 min.再灌注结束即刻取心尖组织,分离线粒体,测定SOD、Na+ -K+ -ATP酶、Ca2+-ATP酶活性和MDA和Ca2+含量.结果 与A组比较,B组和C组线粒体SOD、Na+ -K+ -ATP酶和Ca2+ -ATP酶活性升高,MDA和Ca2+含量降低(P＜0.05),D组和E组上述指标比较差异无统计学意义(P＞0.05);与C组比较,D组和E组线粒体SOD、Na+-K+-ATP酶和Ca2+ -ATP酶活性降低,MDA和Ca2+含量升高(P＜0.05),B组上述指标比较差异无统计学意义(P＞0.05).结论 右美托咪啶后处理可减轻大鼠离体心脏缺血再灌注时的线粒体损伤,其机制可能与抑制线粒体通透性转换孔开放有关.     

Comparing FK-506 with Basic Fibroblast Growth Factor (b-FGF) on the Repair of a Peripheral Nerve Defect Using an Autogenous Vein Bridge Model

ABSTRACT?

Objective: The limited availability of donor sites for nerve grafts and the morbidity associated with their harvesting serve as motivating factors to actively conduct research to find alternatives to the status quo. Experimental and clinical studies have shown that a vein segment used to bridge a peripheral nerve defect leads to a functional nerve repair. Both FK-506 and b-FGF have been reported to enhance peripheral nerve regeneration. This study compared the effects of FK-506 with that of b-FGF on peripheral nerve regeneration in a rat autogenous vein graft conduit model. Methods: The main trunk of the right sciatic nerve was transected and bridged by an autogenous vein in 30 rats. Small osmotic pumps were placed just proximal to the anastomoses. Groups of 10 rats were assigned to receive saline solution, b-FGF (2,000 units), or FK-506 (0.5 mg/kg/day) via the osmotic pumps for 2 weeks. Sciatic nerve regeneration was evaluated by sensory function, walking track analysis, electrophysiologic studies, and light microscopic evaluation. Results: On post-operative day 90, there was a statistically significant difference (p <.005) in nerve regeneration between the rats who received saline compared with those who received FK-506 or b-FGF. This was determined using sensory function tests, sciatic function index, and electrophysiologic studies. The number of nerve axons, as determined by histological analysis, revealed there were significantly more nerve fibers which were regenerated in both experimental groups (FK-506 and b-FGF) when compared with rats who received saline. There was no statistically significant difference in the number of nerve axons that regenerated in rats injected with FK-506 vs. rats injected with b-FGF. Conclusion: FK-506 and b-FGF promote similar nerve regeneration in rats compared with control.     

Protective effect of tadalafil on ischemia/reperfusion injury of rat ovary

Background/Purpose

The aim of the study was to evaluate the effects of tadalafil (TDF) on ischemia/reperfusion (I/R) injury in rat ovaries.

Methods

Thirty-five female Sprague-Dawley rats were randomly divided into 5 groups (n = 7): sham (S), I/R1, I/R2, TDF1, and TDF2. In the I/R1 and TDF1 groups, 3-hour ischemia was followed by 12-hour reperfusion; and in the I/R2 and TDF2 groups, 3-hour ischemia was followed by 24-hour reperfusion. In the TDF groups, 30 minutes before reperfusion, a single dose of 5 mg/kg TDF was administered intraperitoneally. The ovarian tissue levels of malondialdehyde and nitric oxide (NO), and the activities of superoxide dismutase and catalase were measured biochemically. Tissue damage to ovarian tissue was scored by histopathologic examination.

Results

The tissue malondialdehyde levels were significantly higher and the catalase and superoxide dismutase activities were significantly lower in the I/R groups compared with the S and TDF groups (P < .05). The NO levels were significantly higher in the TDF1 group than the S and I/R1 groups (P < .05). Although the NO levels were increased in the TDF2 group compared with the I/R2 group, the difference was not significant. Ovarian tissue damage scores of the I/R groups were significantly higher than those of the S group (P < .05). Treatment with TDF significantly decreased the ovarian tissue damage scores in the TDF groups compared with the I/R groups (P < .05).

Conclusions

Tadalafil is effective in preventing tissue damage induced by I/R in rat ovaries.     

脊髓减压联合电针对急性上颈段重度脊髓压迫损伤影响的实验研究

目的:探究脊髓减压联合电针对急性上颈段重度脊髓压迫损伤大鼠的治疗效果和可能的作用机制。方法:SPF级Wistar大鼠30只随机分为5组(对照组A、B,实验组C、D、E),每组6只,采用经寰枕间隙置入球囊导管加压造成脊髓压迫损伤的方法构建脊髓损伤模型。A组无任何干预,空白对照,B组置入球囊导管后不加压,做假手术对照,C、D、E组加压48 h后松球囊脊髓减压,C组取百会、大椎穴进行电针干预,连续波,频率2 Hz,治疗时间15 min,持续治疗14 d,D组于大鼠尾静脉注射甲强龙进行甲强龙冲击治疗,E组不再行任何治疗干预。14 d后5组大鼠全部行腹主动脉取血和脊髓损伤组织取材,采用BBB评分法对5组大鼠的运动功能进行评价,ELISA法检测损伤组织及血清中血小板活化因子(platele-activating factor,PAF)的含量,Western blot法检测损伤组织中Caspase-9的表达。结果:BBB评分:对照组A、B在实验组压迫后1、48 h,实验组治疗后24 h,3、7、14 d等6个时间点上均为(21.000±0.000)分,实验组评分始终低于对照组,C、D组评分显著高于E组(P0.05),C、D组评分相近(P0.05)。ELISA法测PAF结果显示:A、B、D、E组血清中PAF浓度相近(P0.05),C组血清中PAF浓度较其余4组低(P0.05),A、B组组织中PAF浓度结果相近(P0.05),C组组织中PAF浓度较A、B组高(P0.05),D组组织中PAF浓度较A、B、C组高(P0.05),E组组织中PAF浓度较其余4组高(P0.05);Western blot法检测结果显示:A、B组Caspase-9的表达量相近(P0.05),C组表达较A、B组高(P0.05),D组表达量较A、B、C组高(P0.05),E组表达较A、B、C、D组高(P0.05)。结论:脊髓减压联合电针治疗急性上颈段重度脊髓压迫损伤较脊髓减压联合甲强龙和单纯脊髓减压效果更佳,其作用机制可能与降低脊髓损伤组织中PAF的含量与下调其Caspase-9蛋白的表达有关。     

Effects of high-sodium diet on lithogenesis in a rat experimental model of calcium oxalate stones

BackgroundThis study aimed to investigate the effects of a high- and low-sodium diets on lithogenesis in a rat experimental model of calcium oxalate stones.MethodsTwenty male Wistar rats were randomly divided into four groups; group A: 4% NaCl+1% ethylene glycol (EG); group B: 8% NaCl+1% EG; group C: 8% NaCl+normal drinking-water; group D: 1% EG +normal diet. All rats were sacrificed 4 weeks later, and blood samples were collected from the heart. The kidneys were collected for Von Kossa staining to evaluate the formation of calcium-containing crystals. The last 24-h urine samples were also gathered for metabolic analysis.ResultsVon Kossa staining demonstrated that the rats in both group A and group B had significantly more renal calcium crystals than those in group D. However, 24-h urinary volume increased significantly (142.26±20.91 mL) in group B compared with group A (100.52±28.23 mL), group C (107.36±14.24 mL), group D (40.79±8.71 mL) (P=0.004, 0.012, and 0.000 respectively). Level of urine sodium (Na), potassium (K), chlorine (Cl), and calcium (Ca), urea nitrogen were significantly higher in group B compared with group D. The urine phosphorus, oxalate, and creatinine levels; urine specific gravity; and urine PH were similar between group B and group D. The level of serum sodium was higher in group B (151.26±4.06 mmol/L) compared with group D (145.56±1.12 mmol/L) (P=0.002).ConclusionsA high sodium intake might increase the risk of lithogenesis in susceptible individuals (given by EG) or in individuals with water restriction.     

The Effects of Testosterone on Intestinal Ischemia/Reperfusion in Rats

ABSTRACT

Ischemic injury to the gut is believed to occur in many serious clinical conditions. Our aim was to investigate the postischemia/reperfusion (I/R) effects of exogenously administered testosterone on the intestines of normal and orchiectomized rats.Forty-eight rats were divided into eight groups of six animals: (1) Sham-operated control group; (2) Sham-operated + testosterone-treated group; (3) I/R group: Rats were subjected to the surgical procedures and underwent intestinal ischemia for 60 min followed by reperfusion for 60 min; (4) I/R + testosterone-treated group: Rats were subjected to the surgical procedures and received testosterone 100 mg/kg (i.p.); (5) I/R + orchiectomy group: Rats were subjected to the surgical procedures as well as orchiectomy; (6) orchiectomy group: Rats were subjected to the surgical procedures as well as orchiectomy; (7) orchiectomy + testosterone-treated group: Rats were subjected to the surgical procedures as well as orchiectomy and received testosterone 100 mg/kg (i.p.); and (8) I/R + orchiectomy + testosterone-treated group. The histological findings of this study paralleled the observed degree of lipid peroxidation (LPO) and protein oxidation. Intestinal mucosal injury was extensive in the I/R, I/R + orchiectomy, and I/R + orchiectomy + testosterone groups, but was less in the I/R + testosterone group. Histopathological injury also paralleled the degree of oxidative stress. Apoptotic enterocytes were more numerous in the I/R, I/R + orchiectomy, and I/R + orchiectomy + testosterone groups. Administration of testosterone in the presence of testes significantly protected intestinal tissue against I/R mucosal injuries, while administration of testosterone in the absence of testes did not significantly protect intestinal tissue against I/R mucosal injuries.