首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 250 毫秒
1.
目的: 分析心肌梗死(MI)后大鼠心肌组织中Rho激酶表达的变化,探讨Rho激酶信号通路与心肌细胞凋亡的关系及其选择性抑制剂法舒地尔对MI后心肌的保护作用。 方法: 选取雄性Wistar大鼠,结扎其左前降支建立急性心肌梗死(AMI)模型。将术后24 h存活的24只大鼠随机分为治疗组(n=12)和AMI组(n=12),另随机选取10只大鼠作为假手术组,只在其左前降支下穿线不结扎。治疗组腹腔注射法舒地尔5 mg/kg,每日两次;AMI组和假手术组给予等量的生理盐水。4周后,用Evens蓝及四唑氮蓝试验(NBT)双染确定缺血及梗死面积;用RT-PCR法测定Rho激酶mRNA的表达;DNA片段分析观察心肌细胞凋亡的情况;用免疫组化染色法测定凋亡相关蛋白bcl-2及bax表达的变化。结果: 与AMI组相比,治疗组的梗死面积显著减小(P<0.05)。AMI大鼠缺血心肌组织中DNA片段分析显示,有DNA梯状条带(ladder)形成,假手术组大鼠却没有。AMI组大鼠中Rho激酶mRNA及凋亡相关蛋白bax的表达明显增加(P<0.01,P<0.01);bcl-2的表达明显减少(P<0.01)。以法舒地尔治疗4周后,Rho激酶mRNA及bax的表达均显著减少,bcl-2的表达显著增加(均P<0.01)。结论: MI大鼠心肌组织中Rho激酶的表达升高,心肌细胞凋亡增加。法舒地尔能够减少Rho激酶的表达,减少心肌细胞凋亡,发挥对心肌的保护作用。  相似文献   

2.
目的:探讨法舒地尔对急性心肌梗死(AMI)大鼠炎性细胞因子表达的影响及细胞因子表达与Rho激酶的关系.方法:选取雄性Wistar大鼠,建立大鼠AMI模型,将术后存活大鼠随机分为治疗组(F组)和AMI组;另设假手术组(S组),只在其左前降支下穿线不结扎.F组给予法舒地尔5 mg/kg,AMI组和S组给予等量0.9%氯化钠溶液,腹腔注射,每日2次.4周后,用Nikon 4多导生理记录仪检测血流动力学指标,放射免疫法测血清中肿瘤坏死因子(TNF)-α和白细胞介素-1β(IL-1β)含量,EvensBlue及NBT双染确定缺血及梗死面积,RT-PCR法测定Rho激酶mRNA的表达.结果:与S组相比,AMI组细胞因子TNF-α和IL-1β、左室舒张末压(LVEDP)表达明显升高,而左室收缩压(LVSP)和左室压力上升/下降最大速率(±dp/dtmax)明显减低(P<0.05).与AMI组比较,F组梗死面积显著减小,TNF-α和IL-1β表达水平明显下降,Rho激酶mRNA表达显著减少;F组更明显地降低LVEDP,升高LVSP和±dp/dtmax(P<0.01),左室功能明显改善.结论:法舒地尔可以降低AMI大鼠炎性细胞因子及心肌Rho激酶表达,保护缺血心肌,减少心肌梗死面积,改善心功能.  相似文献   

3.
目的探讨二氮嗪对兔心脏缺血再灌注损伤过程中心肌细胞凋亡和心肌细胞bcl-2和bax基因表达的影响.方法24只兔随机分成假手术组(P组)、缺血再灌注组(IR组)、缺血预适应组(IP组)和二氮嗪组(DP组).阻断和松开左冠脉前降支制作缺血再灌注模型,缺血5 min/再灌注5 min连续3次循环诱导预适应.DP组在缺血前缓慢静脉注射二氮嗪3 mg/kg.再灌注结束后测算左室心肌梗死面积,取缺血区心肌行TUNEL法检测心肌凋亡细胞和免疫组化检测bcl-2和bax蛋白的表达.结果DP组和IP组梗死面积明显小于IR组(P<0.001).凋亡细胞百分数DP组(34±5)%和IP组(32±6)%较IR组(56±8)%显著减少(P<0.001).和IR组相比,bcl-2表达在IP组和DP组明显升高(P均<0.01),bax基因表达在IP组和DP组则明显降低(P均<0.001).结论二氮嗪能通过调节bcl-2和bax的表达来减轻兔心肌缺血再灌注损伤后的心肌细胞凋亡.  相似文献   

4.
目的 观察Rho激酶在大鼠心肌细胞缺血再灌注损伤细胞凋亡中的作用,法舒地尔(fasudil,F)对缺血再灌注损伤细胞凋亡的影响.方法 45只SD大鼠建立缺血再灌注损伤(IPI)模型,实验分3组:(1)空白对照组(C组);(2)缺血再灌注+生理盐水组(IR组);(3)缺血再灌注+法舒地尔组(FH组).Western blot法检测肌球蛋白磷酸酶目标亚单位1(MYPT1)磷酸化水平,作为Rho激酶功能活化的标志,应用流式细胞仪检测心肌细胞的凋亡率.结果 再灌注后MYPT1的磷酸化水平显著增加,IR组磷酸化MYPT1水平是正常对照组的3.66倍(P<0.01).用法舒地尔干预后,FH组磷酸化MYPT1水平较IR组降低36.34%(正常对照组的2.33倍),FH组心肌细胞的凋亡率较IR组呈下降趋势(P<0.01).结论 Rho激酶在缺血再灌注心肌细胞中有促MYPT1磷酸化水平上调作用,法舒地尔可减少缺血再灌注心肌细胞凋亡的发生.  相似文献   

5.
目的:研究藏红花酸预处理对心肌缺血大鼠凋亡相关蛋白bcl-2与bax表达的影响。方法:将30只Wistar雄性大鼠采用结扎冠状动脉左前降支的方法制备心肌缺血模型,缺血45min后,再灌注3h。后随机分为3组,每组10只。假手术组(Sham组)只穿线不结扎;缺血再灌注组(I/R组)0.5%CMC-Na按10ml/kg灌胃1周;藏红花酸组(CRO组)藏红花酸(50mg/kg)灌胃1周。实验结束后用TTC染色测定心肌的梗死面积;免疫组织化学方法检测心肌组织Bax、Bcl-2蛋白的表达;荧光定量PCR方法检测Bax、Bcl-2的mRNA表达。结果:与I/R组比较,CRO组梗死面积、Bax蛋白表达明显降低(P0.01),Bax mRNA表达降低(P0.05);Bcl-2蛋白表达、Bcl-2mRNA表达及Bcl-2/Bax的比值明显升高(P0.01)。结论:藏红花酸预处理对缺血再灌注损伤心肌细胞有保护作用,其机制可能与上调凋亡抑制蛋白Bcl-2、下调促凋亡蛋白Bax的表达有关。  相似文献   

6.
目的:探讨犬实验性心肌梗死延迟再灌注(LR)后对梗死周边缺血区心肌细胞凋亡及凋亡相关基因bcl-2和baxmRNA表达的影响。方法:健康成年杂交犬28只全麻下常规开胸暴露冠状动脉后随机分为3组:假手术(SHAM)组(8只),急性心肌梗死(AMI)组(10只),LR组(10只)。SHAM组仅行左冠状动脉前降支下穿过丝线而不结扎冠状动脉,AMI组行左冠状动脉前降支高位永久结扎,LR组在高位结扎左冠状动脉前降支6h后松解结扎线予以再灌注6h。共有23只犬模型制作成功。各组犬均于术后12h处死,采集心肌标本。使用脱氧脲核苷酸缺口末端标记法检测心肌细胞凋亡,计算心肌细胞凋亡指数(AI)。逆转录聚合酶链反应法检测心肌细胞中bcl-2和baxmRNA表达水平,以β-actin作为内参照。结果:LR组心肌细胞AI较AMI组明显减少(P<0.05)。与SHAM组相比,bcl-2和baxmRNA在AMI组和LR组的表达均升高(P<0.01),但bcl-2mRNA在该2组间差异无统计学意义(P>0.05);而baxmRNA在AMI组的表达较LR组明显增高(P<0.05)。结论:AMI后LR可以减少梗死周边缺血区心肌细胞凋亡,其机制可能与降低心肌细胞baxmRNA的表达有关。  相似文献   

7.
目的:研究阿霉素损伤心肌细胞miRNA378*与网腔钙结合蛋白(calumenin)、内质网应激伴侣蛋白GRP78、凋亡因子bax及bcl-2相关性。方法:实验分6组:对照组、阿霉素组、miRNA378*过表达对照组、miRNA378*过表达组、miRNA378*沉默对照组、miRNA378*沉默组。原代培养乳鼠心肌细胞,采用免疫组织化学方法检测培养乳鼠心室肌细胞α-SMA蛋白,慢病毒质粒转染心室肌细胞,实时荧光定量PCR技术检测各组心肌细胞miRNA378*、calumenin、GRP78、bax及bcl-2mRNA表达。结果:1与对照组相比较,阿霉素组心肌细胞calumenin mRNA表达明显减少(P0.01),GRP78 mRNA表达增加(P0.01),bax mRNA表达增加(P0.01),bcl-2mRNA表达明显减少(P0.01)。2与阿霉素组相比较,miRNA378*过表达组心肌细胞calumenin mRNA表达增加(P0.01),bcl-2mRNA表达增加(P0.01),而GRP78mRNA表达减少(P0.01),bax mRNA表达减少(P0.01)。与阿霉素组相比较,miRNA378*沉默组GRP78、bax mRNA表达增加(P0.01),bcl-2mRNA表达减少(P0.01)。结论:阿霉素损伤可能引起心肌细胞calumenin表达减少进而发生内质网应激;上调miRNA378*表达会增加阿霉素损伤心肌细胞calumenin表达缓解内质网应激,进而抑制心肌细胞凋亡;而沉默miRNA378加重阿霉素损伤心肌细胞内质网应激及促进心肌细胞凋亡。  相似文献   

8.
目的探讨Rho激酶信号通路在心肌梗死模型大鼠心肌细胞凋亡组织中的表达变化及对心肌细胞凋亡的影响作用。方法选取健康雄性Wistar大鼠,通过结扎左前降支建立大鼠心肌梗死模型,将24 h后仍然存活的大鼠选取30只,随机分为模型组和治疗组(法舒地尔5 mg/kg,2次/d)各15只,并另外选取健康雄性大鼠15只作为假手术组,假手术组和模型组给予等量生理盐水处理,比较4 w后3组心肌梗死面积及Rho激酶mRNA、蛋白等指标的表达差异。结果 3组左心室收缩压(LVSP)、左室舒张压(LVEDP)、左室内压最大上升速率(+dp/dtmax)、左室内压最大下降速率(-dp/dtmax)差异均有统计学意义(P0.05),模型组LVSP、+dp/dtmax、-dp/dtmax显著低于治疗组和假手术组(P0.05),LVEDP显著高于治疗组和假手术组(P0.05),治疗组LVSP、+dp/dtmax、-dp/dtmax显著低于假手术组(P0.05),LVEDP显著高于假手术组(P0.05)。治疗组心肌缺血面积低于模型组但差异不显著(P0.05);治疗组心梗面积显著低于模型组(P0.05)。3组Rho激酶mRNA、Bax蛋白、Bcl-2蛋白表达差异有统计学意义(P0.05);组间差异均有统计学意义(P0.05)。结论心肌梗死大鼠心肌组织中的Rho激酶mRNA、Bax蛋白达显著增加,同时Bcl-2蛋白表达降低,法舒地尔能够降低Rho激酶mRNA表达,减少心肌细胞凋亡,减轻心肌梗死面积。  相似文献   

9.
目的 研究Rho激酶抑制剂法舒地尔(fasudil)对大鼠腹主动脉缩窄压力超负荷诱导的心肌肥厚的影响及机制.方法 50只雄性Wistar大鼠随机分为5组:假手术组、压力超负荷模型组、法舒地尔低剂量组、法舒地尔高剂量组及阳性对照(卡托普利)组,每组10只.除假手术组外,其他4组大鼠结扎肾上方腹主动脉制备压力超负荷模型,4周后建立心肌肥厚模型并开始给药,疗程4周.给药结束后,检测各组血流动力学指标,心脏重量指数(HW/BW)及左心室重量指数(LVW/BW);取心肌组织,经不同染色方法,观察心肌病理改变并检测心肌细胞直径(MD)和心肌胶原百分比(CVF);RT-PCR法检测心肌组织中RhoA、Rho激酶mRNA的表达.结果 与假手术组比较,模型组的LVEDP明显增加,LVSP明显下降;HW/BW、LVW/BW明显增加;MD增大(P<0.01),CVF明显增加(P<0.05);RhoA、Rho激酶mRNA的表达明显上调(均P<0.01).与模型组比较,经法舒地尔及阳性药物治疗后,上述指标均有不同程度的改善(均P<0.05,P<0.01).结论 Rho激酶抑制剂法舒地尔可以改善心功能,抑制心肌胶原的合成及心肌纤维化,改善压力超负荷所引起的心肌肥厚.  相似文献   

10.
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.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
The immunoneuroendocrine role of melatonin   总被引:19,自引:0,他引:19  
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.  相似文献   

15.
16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
20.

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号