七氟醚后处理对大鼠离体心肌缺血/再灌注时线粒体融合蛋白2表达及细胞凋亡的影响

目的探讨七氟醚后处理对大鼠离体心肌缺血/再灌注时线粒体融合蛋白2（Mfn2）表达及细胞凋亡的影响。方法健康成年雄性SD大鼠,体重220g~280g,采用随机数字表法,将其分为假手术组（S组）、缺血/再灌注组（I/R组）、七氟醚后处理组（Sev组）。采用Langendorff离体心脏灌流系统建立心肌缺血/再灌注损伤模型。K-H液平衡灌注30min后,S组继续灌注K-H液150min;I/R组停灌30min,复灌120min;Sev组停灌30min后灌注含3%七氟醚饱和的K-H液5min,再用K-H液冲洗10min,继续灌注K-H液,总灌注时间为120min。于再灌注结束时取心肌组织,采用免疫组化法测定Mfn2蛋白表达,TUNEL法测定心肌细胞凋亡,计算心肌细胞凋亡指数（AI）。电镜下观察心肌细胞及线粒体的超微结构。结果与S组比较,I/R组和Sev组Mfn2蛋白表达下调,AI增加（P〈0.05）;与I/R组比较,Sev组Mfn2蛋白表达上调,AI降低（P〈0.05）。电镜结果显示I/R组心肌细胞线粒体出现较重损伤,线粒体膜断裂,嵴不规则或消失。Sev组心肌细胞线粒体损伤较轻,线粒体形态完整。结论七氟醚后处理对大鼠离体心肌缺血/再灌注损伤具有保护作用,其机制可能与上调心肌组织Mfn2表达,保护线粒体形态完整,减少心肌细胞凋亡有关。     

七氟醚后处理对大鼠心肌缺血再灌注氧化应激的影响

目的探讨七氟醚后处理对体内大鼠心肌缺血再灌注损伤时氧化应激的影响。方法选择健康雄性成年SD大鼠64只,随机分为假手术组、单纯七氟醚组、缺血再灌注组和七氟醚后处理组,每组16只。再灌注末,利用动物超声仪测定心功能指标,采用1%TTC测定心肌梗死面积百分比,并检测蛋白羰基化水平、心肌还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)和丙二醛含量以及心肌超氧化物歧化酶2(SOD2)和血红素氧合酶1(HO-1)蛋白表达水平。结果与假手术组比较,缺血再灌注组心功能指标恶化,心肌梗死面积百分比、蛋白羰基化、丙二醛、SOD2和HO-1蛋白表达明显上调,心肌GSH和GSH/GSSG明显降低[(6.43±0.70)nmol/L vs(15.94±2.20)nmol/L,2.04±0.28 vs 4.82±0.50,P0.05]。与缺血再灌注组比较,七氟醚后处理组心功能指标改善,心肌梗死面积百分比、蛋白羰基化、丙二醛明显降低,心肌GSH、GSH/GSSG、SOD2和HO-1蛋白表达明显上调(P0.05)。结论七氟醚后处理可减少体内大鼠心肌缺血再灌注损伤,发挥心肌保护作用,且氧化应激反应是其心肌保护作用的重要机制之一。     

蛋白激酶B/雷帕霉素靶蛋白通路在七氟醚后处理保护心肌缺血再灌注中的作用

目的:探讨七氟醚后处理对离体大鼠心肌缺血再灌注损伤的影响及蛋白激酶B(AKT)/雷帕霉素靶蛋白(m TOR)通路在其中的作用。方法:取Langendorff离体灌注模型成功的大鼠心脏84个,随机分为7组(n=12):假手术组(Sham组)、缺血再灌注组(I/R组)、七氟醚后处理组(SPC组)、NVP-BEZ235溶剂二甲基亚砜组(DMSO组)、磷脂酰肌醇-3-激酶(PI3K)/m TOR双重抑制剂NVP-BEZ235组(BEZ组)、NVP-BEZ235+七氟醚后处理组(BEZ+SPC组)和单纯七氟醚给药组(SEVO组)。除Sham组和SEVO组,其余各组缺血30 min,再灌注120 min。SPC组、DMSO组和BEZ组分别于缺血末至再灌注初15 min给予经2.4%七氟醚、DMSO(0.2%)和NVP-BEZ235(20μmol/L)饱和的K-H液灌注,随后更换为正常K-H液再灌注105 min。BEZ+SPC组于缺血末至再灌注初15 min给予经2.4%七氟醚和NVP-BEZ235(20μmol/L)饱和的K-H液灌注。再灌注末观察各组心肌梗死范围,心肌组织病理学变化,检测蛋白[磷酸化AKT(phospho-AKT)/总的AKT(total-AKT)、磷酸化m TOR(phospho-m TOR)/总的m TOR(total-m TOR)、自噬相关基因6(Beclin1)、B淋巴细胞瘤-2(Bcl-2)相关X蛋白(Bax)/Bcl-2和活化半胱氨酸天冬氨酸蛋白酶-3(cleaved Caspase-3)]表达水平。结果:与I/R组比较,SPC组心肌梗死范围减少[(26.28±4.00)%vs(49.22±3.66)%],心肌病理损伤减轻,phosphoAKT/total-AKT和phospho-m TOR/total-m TOR表达分别上调79.85%和67.02%,Beclin1、Bax/Bcl-2和cleaved Caspase-3表达分别下调33.77%、69.26%和48.84%(P均0.05);与SPC组比较,BEZ+SPC组心肌梗死范围增加[(53.85±4.06)%vs(26.28±4.00)%],心肌病理损伤加重,phospho-AKT/total-AKT和phospho-m TOR/total-m TOR表达分别下调46.06%和42.95%,Beclin1、Bax/Bcl-2和cleaved Caspase-3表达分别上调29.90%、206.85%和114.65%(P均0.05)。结论:七氟醚后处理可通过激活AKT/m TOR通路,抑制心肌细胞自噬和凋亡,从而减轻离体大鼠心肌缺血再灌注损伤。     

缺血后处理对心肌的保护作用及其机制探讨

目的:探讨缺血后处理对大鼠心肌缺血再灌注损伤的预防作用。方法:将32只雄性SD大鼠随机均分为假手术组(Sham组)、缺血再灌注组(IR组)、缺血后处理组(IPO组)和环孢素A(CsA)组,采用结扎冠状动脉左前降支制备大鼠心肌缺血-再灌注模型。测定各组心肌组织中肌酸激酶(CK)和丙二醛(MDA)浓度,电镜观察心肌细胞线粒体形态和超微结构改变,并采用免疫组织化学方法测定凋亡相关指标细胞色素C(CytC)的表达。结果:①与IR组相比,IPO组CK活性和MDA含量显著降低(均P<0.01),心肌细胞线粒体超微结构的损伤减少,CytC的胞质表达水平亦降低;②IPO组和CsA组在CK活性与MDA含量上差异无统计学意义,心肌线粒体超微结构损伤程度和CytC的胞质表达水平近似。结论:缺血后处理与CsA有类似的减轻心肌再灌注损伤的作用。     

法舒地尔通过调节线粒体膜通透性转换孔的开放减少大鼠缺血再灌注心肌损伤

目的通过观察法舒地尔及线粒体膜通透性转换孔(mitochondrial permeablity transition pore,MPTP)开放剂苍术苷干预下大鼠缺血再灌注心肌的坏死和凋亡情况,探讨法舒地尔是否通过调节MPTP的开放减轻大鼠缺血再灌注心肌损伤。方法 25只Sprague-Dawley(SD)雄性大鼠按随机数字表法随机分为5组(每组5只),除了空白对照组外,建立在体大鼠心肌缺血再灌注模型(缺血35 min,再灌注120 min)。分别予以法舒地尔(0.5 mg/kg)、苍术苷(5 mg/kg)、法舒地尔+苍术苷干预。用3,5一氧化三苯基四氮唑(TTC)检测大鼠心肌梗死面积,末端脱氧核糖核苷酸转移酶介导的dUTP缺口末端标记法(TdT-mediated dUTP nick end labeling,TUNEL)法检测大鼠心肌凋亡。结果法舒地尔组的心肌梗死面积明显比缺血再灌注组的减少,差异有统计学意义(22%±8.2% vs.41%±6.4%,P0.05);苍术苷组的心肌梗死面积与缺血再灌注组的比较,差异无统计学意义(P0.05);法舒地尔+苍术苷心肌梗死面积比法舒地尔组的增大,两者比较差异有统计学意义(32%±8.5% vs.22%±8.2%,P0.05)。与缺血再灌注组比较,法舒地尔组心肌细胞凋亡细胞数下降,差异有统计学意义(10.3±4.5 vs.18.7±5.4,P0.05);法舒地尔+苍术苷组心肌细胞凋亡指数比法舒地尔组大,差异有统计学意义(13.5±5.2 vs.10.3±4.5,P0.05)。结论法舒地尔可能通过调节MPTP的开放减少大鼠缺血再灌注心肌损伤。     

作者单位：030001山西省太原市 山西医科大学基础医学院生理学系,细胞生理学山西省重点实验室通讯作者：贺忠梅,E-mail：hezmei@126.com

目的 探讨低氧诱导因子-1α(HIF-1α)稳定表达对大鼠心肌缺血再灌注细胞凋亡的影响及可能机制。方法 采用结扎冠脉左前降支45min,再灌注3h的方法,构建大鼠心肌缺血再灌注损伤模型;实验分为假手术组(Sham)、心肌缺血/再灌注组(MI/R)、HIF-1α活化剂DMOG 心肌缺血/再灌注组(D MI/R)、HIF-1α抑制剂YC-1 心肌缺血/再灌注组(YC-1 MI/R);采用全自动生化分析仪测定血清心肌酶(CK-MB,LDH)活性;Western blot检测心脏组织HIF-1α蛋白表达;Evens blue/TTC染色测定心肌梗死面积;TUNEL染色及Caspase-3,8,9活性测定心肌细胞凋亡。结果 (1)与MI/R 组相比,D MI/R 组的HIF-1α蛋白表达量明显增加,心肌酶CK-MB、LDH的活性降低,心肌梗死面积明显减小,并且心肌组织的病理损伤减轻;(2)稳定HIF-1α表达可明显降低心肌细胞凋亡率,且部分逆转了缺血再灌注后心肌组织Caspase-9与Caspase-3的活性升高。结论 HIF-1α稳定表达可抑制线粒体途径介导的心肌细胞凋亡,从而发挥对缺血再灌注损伤的心脏保护效应。     

阿托伐他汀后处理对GK大鼠心肌缺血再灌注损伤的保护作用

目的探讨不同剂量阿托伐他汀后处理对GK大鼠心肌缺血再灌注损伤的作用及其机制。方法将70只GK大鼠随机分为7组(n=10只):假手术组、缺血再灌注组(I/R组)、不同剂量(0.1、0.5、1及2 mg/kg)阿托伐他汀后处理组及阿托伐他汀后处理+LY294002组。TTC染色测定心肌梗死面积,电镜观察心肌细胞超微结构变化及Western blot测定心肌组织磷酸化蛋白激酶B(p-Akt)、总Akt(t-Akt)的蛋白表达。结果阿托伐他汀后处理组心肌梗死面积低于I/R组,心肌线粒体超微结构损伤轻于I/R组,Akt磷酸化水平高于I/R组,其中1 mg/kg和2 mg/kg阿托伐他汀后处理组较显著。PI3K特异性抑制剂LY294002可消除这种作用。结论阿托伐他汀后处理对GK大鼠心肌缺血再灌注损伤有保护作用,这可能与PI3K/Akt通路的激活有关。     

Drp1和自噬在七氟醚后处理大鼠心肌保护中的作用

目的探究动力相关蛋白1(Drp1)和自噬在七氟醚后处理心肌保护中的作用。方法健康成年雄性SD大鼠45只,体重200~230g,采用随机数字表法分为假手术组(Sham组)、缺血再灌注组(I/R组)和七氟醚后处理组(SpostC组),各15只。采用左冠状动脉结扎30min、松开扎线120min的方法制备大鼠心肌缺血再灌注模型,Sham组只穿线不结扎,SpostC组于再灌注前吸入2.5%七氟醚5min。以TTC染色法测量大鼠心肌梗死面积(IS),以Western-blot法测定Drp1及自噬相关蛋白微血管相关蛋白轻链3-Ⅱ(LC3-Ⅱ)的表达,以苏木精-伊红(HE)染色法观察心肌损伤变化。结果Sham组存在Drp1及LC3-Ⅱ蛋白低表达;与Sham组比较,I/R组Drp1及LC3-Ⅱ蛋白表达上调,IS值增加(P<0.05),HE染色结果示心肌损伤加重;与I/R组比较,SpostC组Drp1及LC3-Ⅱ蛋白表达下降,IS值减小(P<0.05),HE染色结果示心肌损伤减轻。结论正常心肌细胞中存在低水平自噬,Drp1介导的自噬在七氟醚后处理心肌保护中具有重要作用。     

线粒体连接蛋白43参与缺血后处理对兔急性心肌缺血再灌注损伤的保护作用

目的 探讨线粒体连接蛋白43(connexin43,Cx43)和线粒体ATP敏感性钾通道(mitoK_(ATP)~+)在缺血后处理保护兔心肌缺血再灌注损伤中的作用.方法 新西兰大白兔64只,建立心肌缺血再灌注模型,给予冠状动脉左前降支30 min缺血,240 min再灌注.随机分为4组,每组16只:假手术组、缺血再灌注组、缺血后处理组和5-羟葵酸加缺血后处理组.测定血浆磷酸肌酸激酶同工酶(CK-MB),肌钙蛋白I(cTnI)含量以及心肌梗死面积,采用电子显微镜观测心肌线粒体结构变化,Western blot检测线粒体Cx43蛋白表达.结果 缺血后处理组心肌梗死面积为(19.1±3.9)%,明显低于缺血再灌注组(35.7±5.8)%,P＜0.01.再灌注4 h末血浆CK-MB与cTnI活性,缺血后处理组明显低于缺血再灌注组和5-羟葵酸加缺血后处理组(P＜0.01).与假手术组比较,其他各组线粒体均损伤明显(P均＜0.01);缺血后处理组线粒体损伤程度轻于缺血再灌注组(P＜0.01);缺血后处理组线粒体损伤程度明显轻于5-羟葵酸加缺血后处理组(P＜0.01).缺血再灌注组和5-羟葵酸加缺血后处理组线粒体Cx43蛋白表达均显著低于假手术组(P均＜0.05);缺血后处理组心肌线粒体Cx43蛋白表达明显高于缺血再灌注组(P＜0.05);缺血后处理组心肌线粒体Cx43蛋白表达明显高于5-羟葵酸加缺血后处理组(P＜0.05).结论 线粒体Cx43可能参与了缺血后处理的心肌保护作用,其机制可能与mitoK_(ATP)~+有关.     

HIF-1α在七氟醚后处理减轻大鼠心肌缺血再灌注致线粒体功能损伤中的作用研究

目的探讨缺氧诱导因子-1α(HIF-1α)在七氟醚后处理减轻大鼠心肌缺血再灌注致线粒体功能损伤中的作用。方法取Langendorff离体灌注模型成功的大鼠心脏88例,采用随机数字表法分为4组(n=22):对照组(C组)、缺血再灌注组(I/R组)、七氟醚后处理组(Spost组)和HIF-1α抑制剂2ME2组(2ME2组)。Western blot测定HIF-1α表达水平;电镜观察线粒体超微结构;汉莎氧电极法测定线粒体3态呼吸(State3)、呼吸控制比(RCR);ATP试剂盒检测ATP含量;线粒体膜电位检测试剂盒检测膜电位变化。结果与I/R组比较,Spost组HIF-1α表达上调,State3、RCR、ATP、膜电位升高(P0.05)。结论 HIF-1α表达上调改善线粒体功能是介导七氟醚后处理减轻大鼠心肌缺血再灌注损伤的重要调控机制。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.