急性缺血与L-精氨酸干预对大鼠心肌组织一氧化氮合酶基因表达的影响

目的观察急性心肌缺血状态下大鼠心脏内皮型和诱生型两种一氧化氮合酶表达和左旋精氨酸（L-Arg）对大鼠心脏组织内生型一氧化氮合酶（eNOS）基因表达的影响。方法60只健康成年SD大鼠随机分为假手术组、缺血组两组。分别取1、2、8、24h四个不同时间点。采用开胸结扎冠状动脉左前降支的方法建立心肌缺血模型,用逆转录聚合酶链式反应（RT-PCR）检测大鼠心梗后不同时间点及L-Arg（30mg·kg-1·次^-1×3）给药后缺血心肌eNOSmRNA表达;免疫组织化学方法检测冠脉结扎后8h缺血心肌诱生型一氧化氮合酶（iNOS）蛋白。结果①冠脉结扎后2h缺血组大鼠缺血心肌组织eNOSmRNA表达下降（P〈0.05）,并持续至结扎后24h;梗死后24h组eNOS mRNA表达与结扎后2h组相比无显著性差异（P〉0.05）。②与生理盐水组相比,L-Arg静脉注射可增加冠脉结扎后大鼠缺血心肌组织细胞eNOS mRNA表达（P〈0.05）。③冠脉结扎后8h,梗死及周围区存活心肌组织细胞出现大量iNOS蛋白表达,而假手术组未见iNOS蛋白表达。结论①正常心肌组织有eNOS基因表达,无iNOS蛋白表达;心肌急性缺血刺激早期诱导大鼠缺血心肌细胞iNOS蛋白大量表达。②在心梗早期缺血心肌组织细胞eNOS基因表达减少。③L-Arg静脉用药可增加急性心肌梗死大鼠缺血心肌组织细胞eNOS mRNA表达。     

急性心肌梗死大鼠心脏一氧化氮合酶表达的改变

目的 通过建立大鼠心肌梗死模型，观察急性心肌梗死对大鼠心脏内皮型一氧化氮合酶mRNA和诱导型一氧化氮合酶蛋白表达的影响。方法48只健康成年SD大鼠（体重200～250g）随机分为假手术组和缺血组，取1、2、8和24h四个不同时间点观察。采用开胸结扎冠状动脉左前降支建立心肌缺血模型，逆转录聚合酶链反应检测大鼠心肌梗死后1、2及24h三个时段缺血心肌内皮型一氧化氮合酶mRNA的表达；免疫组织化学染色检测冠状动脉结扎后8h缺血心肌诱导型一氧化氮合酶蛋白的表达。结果冠状动脉结扎后2h，缺血组大鼠缺血心肌组织内皮型一氧化氮合酶mRNA表达下降（P〈0．05），并持续至结扎后24h；结扎后24h组内皮型一氧化氮mRNA的表达与结扎后2h组相比无显著性差异（P〉0．05）。冠状动脉结扎后8h，梗死区存活心肌组织细胞诱导型一氧化氮合酶蛋白大量表达，而假手术组未见诱导型一氧化氮合酶蛋白表达。结论正常大鼠心肌组织有内皮型一氧化氮合酶基因表达，无诱导型一氧化氮合酶蛋白表达。在心肌梗死早期缺血心肌内皮型一氧化氮合酶mRNA表达减少。心肌急性缺血刺激早期诱导大鼠缺血心肌组织诱导型一氧化氮合酶蛋白大量表达。     

缺血预处理对心肌梗死大鼠心肌肝细胞生长因子表达的影响

目的 通过观察大鼠心肌梗死和远距缺血预处理后缺血心肌中肝细胞生长因子(HGF)基因表达的变化,探讨HGF在远距缺血预处理中的作用.方法　实验分组:①急性心肌梗死组;②下肢缺血预适应组:夹闭双侧股动脉后再灌注,重复4次后结扎左前降支.③肾缺血预适应组:夹闭双侧肾动脉再灌注,重复3 次后结扎左前降支.④正常对照组.用evans-TTC染色法区分梗死区和缺血区心肌,切取梗死区心肌及缺血区心肌并称重.用RT-PCR法检测大鼠缺血区心肌HGF mRNA表达.结果 除了正常对照组外其他三组缺血程度无明显差异;而肾缺血预处理组心肌梗死程度(46.18%±6.15%)、下肢缺血预处理组梗死程度(46.92%±6.69%)较急性心肌梗死组(66.44%±13.68%)相比均降低约30%(P＜0.05).肾缺血预处理组及下肢缺血预处理组4、6、12 h HGF mRNA表达较急性心梗组各时间点降低(P＜0.01).结论 提示HGF可能是远距缺血预处理减少梗死区面积的机制之一.     

红花黄色素对兔缺血再灌注心肌的保护作用

目的探讨红花黄色素对缺血再灌注心肌血清氨基末端B型脑钠肽前体(NT-proBNP)、CRP水平和Akt、eNOS及PKC蛋白表达的影响。方法将24只新西兰大白兔随机分为3组,每组8只。缺血再灌注组(IR组):结扎冠状动脉前降支1 h,再灌注4 h。缺血预处理组(IPC组):反复短暂3次结扎冠状动脉(结扎3 min,松开5 min,循环3次),然后结扎前降支1 h,再灌注4 h。红花黄色素组(SY组):于再灌注前10 min耳缘静脉注射红花黄色素10 mg/kg,余同IR组。各组于结扎前、再灌注1 h、再灌注4 h取血清检测NT-proBNP、CRP水平;实验结束,取缺血坏死区心肌观察Akt、eNOS以及PKC蛋白表达的变化。结果 SY组和IPC组血清NT-proBNP、CRP水平均低于IR组(P<0.05),心肌组织Akt、eNOS及PKC水平高于IR组(P<0.05)。结论红花黄色素和缺血预处理一样能减轻缺血再灌注损伤。     

肾动脉性高血压大鼠血清一氧化氮、血管紧张素Ⅱ和超氧阴离子水平的变化

目的　探讨一氧化氮、血管紧张素Ⅱ和超氧阴离子 (O2 -)在高血压发病机制中的作用。方法　将体重2 5 6～ 2 85g雄性Wistar大鼠随机分成 5组 ,每组 10只 ,实验前测量血压、心率。对照组进行假手术及常规饮食喂养 ,单纯结扎组 :不完全结扎一侧肾动脉及常规饮食喂养 ,结扎 +Losartan组 :不完全结扎一侧肾动脉并在水中加入Losartan2 0mg·kg-1·d-1,结扎 +精氨酸 (L Arg)组 :不完全结扎一侧肾动脉并在水中加入L Arg 2g·kg-1·d-1,结扎 +L Arg +Losartan组 :不完全结扎一侧肾动脉并在水中加入L Arg 2g·kg-1·d-1和Losartan 2 0mg·kg-1·d-1,结扎后 1周测量血压、心率并取血测血管紧张素Ⅱ (AngⅡ ) ,环岛苷磷酸 (cGMP) ,一氧化氮 (NO) ,一氧化氮合成酶 (NOS) ,O2 -,超氧化物歧化酶 (SOD)浓度。结果　单纯结扎组收缩压较结扎前明显升高 (P <0 0 5 ) ,而结扎 +Losartan组收缩压较单纯结扎组明显减低 (P <0 0 5 ) ,结扎 +L Arg组血压较对照组增加 ,但较单纯结扎组降低 ,较结扎 +Losartan组高 (P <0 0 5 ) ,结扎 +L Arg +Losartan组血压较对照组增加 ,但低于单纯结扎组和结扎 +L Arg组 (P <0 0 5 )。实验前、后各组心率无变化(P >0 0 5 )。单纯结扎组AngⅡ较对照组明显升高 (P <0 0 5 ) ,而结扎 +Losart     

一氧化氮在重复可逆性心肌缺血再灌注所致的心肌顿抑时的动态变化及其意义

目的　了解在重复可逆性心肌缺血再灌注所致的心肌顿抑时 ,血液中一氧化氮 (NO)的动态变化及其与心功能的关系 ,并采取促进或抑制NO的方法 ,观察心功能的变化规律。方法　新西兰兔 15只 ,随机分为 3组 (每组 5只 ) :分别为对照组、在静脉内注射NO合成底物L 精氨酸为L Arg组、在静脉内注射一氧化氮合酶抑制剂L 硝基 精氨酸为L NNA组。兔用戊巴比妥钠静脉注射麻醉后 ,结扎前降支制成心肌缺血再灌注模型 ,用电子自旋共振法测定血液中NO含量 ,同时记录左心室最大上升速率dP dtmax、左心室舒张末压力、心率、血压。使兔心肌缺血 10min ,共 3次 ,第 1、2次缺血后再灌注 10min ,第 3次缺血后再灌注 12 0min。结果　 3组的dP dtmax在第 1次缺血 5min时已经下降。但是在第 1次再灌注 5min时L Arg组NO明显升高 ,与对照组比较 ,P <0 .0 5 ;L NNA组NO明显下降 ,与对照组比较 ,P <0 .0 1;L Arg组dP dtmax明显下降 ,与对照组比较 ,P <0 .0 5 ;L NNA组dP dtmax明显改善 ,与对照组比较 ,P <0 .0 5。结论　再灌注早期NO的大量生成是加重心肌顿抑的原因之一。     

自发性高血压大鼠血清和心肌一氧化氮浓度的变化及L-精氨酸对其抑制作用

目的 :观察补充左旋精氨酸 4周后 12～ 13周龄自发性高血压大鼠 (SHR)血清和心肌组织一氧化氮(NO)浓度及血压的变化。方法 :通过腹腔注射补充NO合成前体———左旋精氨酸 (L Arg) 4周 ,硝酸还原酶法测定血清和心肌组织NO浓度 ;鼠尾压测量仪测量大鼠尾动脉的收缩压。结果 :治疗组SHR与对照组SHR相比心肌NO浓度降低 (P <0 .0 5 ) ,两组间血清NO浓度、血压差异无显著性意义 (P >0 .0 5 )。结论 :SHR 12～ 13周龄时体内NO呈代偿性地升高 ,通过腹腔注射慢性补充L Arg 4周使心肌组织NO浓度下降 ,但未能降低SHR已形成的高血压。     

血红素加氧酶-1在远端缺血预适应心肌梗死大鼠心肌中的表达

目的 观察血红素加氧酶-1(HO-1)及其产物在肾缺血预适应后的心肌梗死大鼠心肌中表达,探讨其在缺血预适应后心肌梗死大鼠心肌中的作用.方法 实验分为2大组:心梗组及其假手术组和肾缺血预适应组及其假手术组.心梗组和肾缺血预适应组又分2、4、6、12 h组;假手术组实验结束即处死;取12 h组用伊文思蓝和TTC染色检测心肌梗死面积.用全自动生化仪检测血清中肌酸激酶的同工酶(CK-MB)和胆红素.用放免法检测血清中的铁蛋白;用逆转录多聚酶链反应(RT-PCR)检测心肌组织中HO-1基因的表达.结果 肾缺血预适应组心肌梗死面积比心梗组明显降低;血清中各时间点铁蛋白和总胆红素的含量比心梗组明显升高;而CK-Mb含量比心梗组明显降低;心肌组织中HO-1的表达比心梗组明显升高.结论 肾缺血预适应能够减小心肌梗死面积,对心肌损伤具有保护作用.     

下肢缺血预处理对大鼠心肌基因表达的影响

目的 通过观察经下肢缺血预处理的心肌梗死大鼠心肌中缺氧诱导因子-1α(HIF-1α)和血红素加氧酶-1(HO-1)mRNA的表达,探讨其在缺血心肌中的作用.方法 将SD雄性大鼠随机分为心肌梗死组(40只)和下肢缺血预处理组(40只);每组按缺血时间又分为1、2、4、6、12 h组.显微镜下计数外周血白细胞;HE染色观察心肌组织中浸润白细胞的数值.应用逆转录多聚酶链反应(RT-PCR)测定术后各时间点心肌组织中HIF-1α和HO-1mRNA表达.结果 下肢缺血预处理后12 h组外周血白细胞计数以及心肌组织中白细胞浸润数目较心梗组显著减少(P＜0.05);心肌中1、2、4 h HIF-1α mRNA表达与心梗组对应时间点比较有显著差异(P＜0.01).各时间点HO-1mRNA表达与心梗组对应时间点比较有显著差异(P＜0.01). 结论经下肢缺血预处理后,心肌损伤减轻,HIF-1α和HO-1可能与心肌保护作用有关.     

比索洛尔对一氧化氮和内皮型一氧化氮合酶昼夜节律的影响

目的探讨比索洛尔对大鼠一氧化氮和内皮型一氧化氮合酶(eNOS)及心肌组织eNOSmRNA表达水平昼夜节律的影响。方法健康雄性SD大鼠128只,体质量250～300g,随机分为4组:7:00灌药组(早灌药组)、19:00灌药组(晚灌药组)、7:00对照组(早对照组)、19:00对照组(晚对照组),每组32只。每日早灌药组与晚灌药组均给予比索洛尔3mg/kg灌服,两对照组分别于7:00与19:00给予相同剂量的安慰剂灌服。4周后,分别于同日内不同时间点(2:00,8:00,14:00,20:00)处死4大组大鼠中各8只大鼠,留取血清和心肌组织。分别采用比色法和硝酸还原法、逆转录多聚酶链反应法检测血和心肌组织中eNOS、一氧化氮的含量或活性以及eNOSmRNA的表达水平。结果两灌药组之间、两对照组之间血清及组织一氧化氮、eNOS含量或表达差异无统计学意义(均P>0.05),但灌药组和对照组之间血清及组织一氧化氮、eNOS含量或表达差异有统计学意义(均P<0.05),灌药组的一氧化氮、eNOS含量明显升高,eNOSmRNA的表达增强(P<0.05)。各组血清及组织一氧化氮、eNOS含量或表达均存在昼夜节律,灌药组部分节律振幅、峰值改变。灌药组和对照组各组的组织eNOSmRNA存在典型昼夜节律,节律振幅无差异。早、晚灌服比索洛尔对于一氧化氮、eNOS以及eNOSmRNA昼夜节律的影响有所不同。结论比索洛尔升高血清及组织一氧化氮、eNOS的含量,促进组织eNOSmRNA的表达。比索洛尔可对内皮源性血管活性物质的时间生物学特征产生影响,用药时间不同,对各参数的影响亦有所不同。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

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.     

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.