蒙药野罂粟对腹泻大鼠脏器AC、cAMP、cGMP含量影响的实验研究

本文研究野罂粟对实验动物脏器中腺苷酸环化酶（AC）、环磷酸腺苷（cAMP）、环磷酸鸟苷（cGMP）含量的影响,探讨野罂粟作用的脏器归属.采用双抗体夹心酶联免疫吸附法（ELISA）测定各脏器组织中AC、cAMP、cGMP含量.与模型组比较,野罂粟降低大鼠心内AC含量,升高脾、大肠、小肠内AC含量;降低大肠内cAMP含量,升高胃内cAMP含量;降低肺内cGMP含量,升高大肠、脑内cGMP含量;降低大肠内cAMP/cGMP比值.结果发现野罂粟作用后,胃、肺、大肠内环核苷酸浓度变化显著.     

荷人鼻咽癌裸鼠血浆MDA,cAMP/cGMP及PSP对其影响的研究

利用BALB/c裸鼠,通过移植人低分化鼻咽癌细胞(CNE-2)复制荷人鼻咽癌(NPC)裸鼠模型,检测荷瘤鼠血浆MDA、cAMP、cGMP和cAMP/cGMP比值,以探讨cAMP/cGMP比值改变的原因和机理;观察云芝糖肽(PSP)对荷人NPC裸鼠的抑瘤作用及对荷瘤鼠血浆MDA、cAMP、cGMP和cAMP/cGMP比值影响,以探讨PSP抑瘤机理。结果发现荷瘤裸鼠血浆MDA(18.25±1.37nmol/m1)与正常裸鼠(10.83±1.18)比,差异非常显著(P<0.01);荷瘤鼠血浆cAMP(71.83±8.51pmol/ml)与正常裸鼠(94.77±4.65)比差异显著(P<0.05);荷瘤鼠血浆cGMP(15.77±0.65pmol/ml)与正常裸鼠(28.20±5.31)比差异非常显著(P<0.01);荷瘤鼠cAMP/cGMP比值(4.55±0.35)与正常鼠(3.37±0.37)比差异非常显著(P<0.01)。用高低浓度PSP对荷人NPC裸鼠进行了三批实验,每批实验均有明显抗癌作用(P<0.01),抑瘤率59.58—95.53％,并可降低荷瘤鼠血浆、组织MDA,提高血浆cAMP、cGMP水平,恢复cAMP/cGMP比值。木实验提示,荷瘤鼠血浆cAMP等降低与MDA的提高有关;PSP对荷人NPC裸鼠有抑瘤作用,其抑瘤机理可能是通过降低荷瘤鼠血浆,组织MDA,提高cAMP、cGMP水平,恢复cAMP/cGMP比值。     

急性脑缺血家兔针刺前后环核苷酸及血管紧张素Ⅱ研究

28只大耳白兔随机分成对照组(8只),急性脑缺血组(8只)和针刺组(12只)。夹闭兔两侧颈总动脉使颅内血压急剧下降,制造急性脑缺血动物模型。分别测定正常,夹闭时和针刺“人中”穴后家兔脑及血浆中cAMP、cGMP和AⅡ含量。结果发现:急性脑缺血时,cAMP、cGMP浓度和cAMP/cGMP比值下降,脑中AⅡ浓度下降而血浆AⅡ浓度升高。针刺“人中”后。可明显升高脑及血浆cAMP和AⅡ水平,为临床针刺治疗脑血管意外疾病提供了科学依据。     

针刺调节实验性心律失常的机理研究——对心肌内cAMP/cGMP水平的影响

采用蛋白结合法与放射免疫法测定了大鼠左心室肌cAMP与cGMP含量。麻醉大鼠仅给电针刺激,心室肌cAMP和cGMP水平都有所下降,但cAMP/cGMP比值保持正常。乌头碱诱发快速型心律失常后,心室肌cAMP明显下降,cGMP略有下降,而cAMP/cGMP比值也明显下降。电针刺激“内关”、“神门”能使cAMP值回升,并使cAMP/cGMP比值趋向对照值。异搏定诱发缓慢型心律失常后,心室肌cAMP水平显著升高,cGMP无明显变化,而cAMP/cGMP比值明显高于对照值。电针治疗能使cAMP下降,cGMP升高,从而使cAMP/cGMP比值趋向对照值。针刺对异常cAMP、cGMP水平以及异常cAMP/cGMP比值有调节趋向对照值的作用。这种调节作用是双重的,高于正常生理水平则降低之,低于正常生理水平则升高之,可称为“推挽”调节作用。切断两侧颈部迷走神经后,针刺不再显示这种调节作用。在整体实验中,针刺“内关”、“神门”既可缩短快速型心律失常持续时间,又可缩短缓慢型心律失常持续时间。本实验为针刺在整体和器官水平的疗效提供了分子生物学基础。     

第二信使环腺苷酸和环鸟苷酸检测方法研究进展

环腺苷酸(cAMP)和3′,5′-环鸟苷酸(cGMP)是真核细胞内常见的调节众多功能的第二信使,最近以cAMP/cGMP信号通路为靶点研发的功能食品也越来越多,因此检测cAMP/cGMP的含量至关重要。介绍了放射性同位素法、均相非放射性同位素法、非均相非同位素法等近年来广泛使用的cAMP/cGMP检测方法的原理及其实际应用情况,分析了各种方法的优缺点及灵敏度。其中,荧光共振能量转移技术、均相时间分辨荧光共振能量转移技术、极化荧光检测技术等均相非放射性同位素法因其操作便捷、特异性强、灵敏度高而适用于cAMP/cGMP的高通量检测。     

血管生成素在脉络膜新生血管中的作用

脉络膜新生血管与眼部许多疾病有关,是引起视力障碍的重要原因之一.血管生成素(Ang)是一类特异性作用于血管内皮细胞的细胞因子,其中Ang-1和Ang-2与血管生成素受体Tie-2结合后构成的Ang/Tie-2信号传导系统在脉络膜新生血管的发生过程中起着重要的作用.本文就血管生成素家族成员及其受体与脉络膜新生血管生成机制的关系综述如下.     

人参汤提取物对血管内皮细胞保护作用的研究

探讨人参汤提取物对血管内皮细胞的保护作用.采用体内、外血管内皮细胞损伤模型,测定体外血管内皮细胞破裂MTT染色后的OD值、体内血管内皮细胞损伤时血中CEC数及血清中NO的浓度.体外实验人参汤各剂量组的OD值比模型对照组降低(P<0.05)、体内实验人参汤各剂量组CEC数量、NO浓度比模型对照组都显著降低(P<0.01).实验结果表明,人参汤提取物对血管内皮细胞的损伤具有保护作用.     

磁场对AMI心肌的保护作用──磁场对大鼠实验性AMI血浆cAMP cGMP,血清Mg~( )含量变化的影响

本实验将大鼠随机分为五组：空白对照组、磁作用对照组、AMI组、AMI药物（心得安）治疗组。AMI磁场治疗组。采用放射免疫方法和原子分光光度法测定各组大鼠血浆cAMP、cGMP，血清Mg 含量。结果表明：AMI磁场治疗组血浆cAMP、cGMP，含量及cAMP／cGMP比值均明显低于AMI组（P＜0．05），与药物治疗组近似，略高于空白对照组和磁作用对照组空白对照组和磁作用对照组最低、两组间无显著差异。AMI磁场治疗组血清Mg＋．含量明显高于AMI组（P＜0．05），与药物治疗组近似。略低于空白对照组、磁作用对照组，空白对照组和磁作用对照组最高，两组间无显著差异。证实了磁场对动物实验性AMI，心肌的保护作用，为磁场用于AMI的治疗提供实验依据。     

大鼠虚寒证模型部分指标相关性的初步研究

目的　在改进虚寒证模型的基础上对其部分指标的相关性进行初步研究。方法　雌性WistarⅡ级大鼠 ,按体温分为对照组和虚寒证组。虚寒证组用寒凉方药造模 ,用量较大 ,时间较长。检测宏观和微观多项指标 ,分析指标的相关性。结果　相对于对照组 ,虚寒证组指标的相关性有其特点。如各内脏器官重量 (包括指数 )间的相关性明显增强 ;游泳时间与LDH活性和cAMP cGMP比值呈负相关 ,与cGMP含量呈正相关 ;胸腺重量、指数与cAMP cGMP比值、皮质醇含量呈正相关 ,与E2 含量、E2 T比值含量呈负相关 ;虚寒证组脾脏小动脉周围淋巴鞘直径与脾脏重量和指数呈正相关 ;胃粘膜改变与内分泌系统相关性较强等。结论　生物学特性的相关性同样为机体的重要生理病理特征 ,应引起重视     

反义核酸Ⅷ C真核表达载体的构建及其对转化血管内皮细胞的影响

利用人工合成的部分反义核酸ⅧC(以pⅧC表示)用以构建含有部分反义凝血因子基因片段的真核表达质粒pXJ41-neo/pⅧC,再用磷酸钙介导转染血管内皮细胞,筛选出阳性克隆血管内皮细胞,扩大培养转基因细胞,用金黄色葡萄球菌凝集试验和酶联免疫吸附试验(ELISA)检测转基因细胞ⅧC蛋白质的表达水平.结果表明所构件人工合成的部分反义核酸pⅧC真核表达载体能有效抑制人的凝血因子ⅧC的表达,因此建立了有效表达反义核酸pⅧC的血管内皮细胞模型.     

重构新型血管内皮生长因子在毕赤酵母中的表达、纯化与功能鉴定

血管内皮细胞生长因子为内皮细胞特异的刺激因子,在缺血治疗中具有应用前景.本文通过PCR的方法将VEGF165纤溶酶酶切位点突变并将肝素结合域融合到VEGF165的C末端,且将其进行了酵母表达,并纯化了酵母表达产物,对它的生物活性进行了初步鉴定.结果表明,改构的VEGF可形成蛋白二聚体,且仍保留体外刺激血管生成的能力.VEGF的重构成功与表达产物的获得,为进一步研究其功能奠定了基础.     

Identification of an angiogenic mitogen selective for endocrine gland endothelium

The known endothelial mitogens stimulate growth of vascular endothelial cells without regard to their tissue of origin. Here we report a growth factor that is expressed largely in one type of tissue and acts selectively on one type of endothelium. This molecule, called endocrine-gland-derived vascular endothelial growth factor (EG-VEGF), induced proliferation, migration and fenestration (the formation of membrane discontinuities) in capillary endothelial cells derived from endocrine glands. However, EG-VEGF had little or no effect on a variety of other endothelial and non-endothelial cell types tested. Similar to VEGF, EG-VEGF possesses a HIF-1 binding site, and its expression is induced by hypoxia. Both EG-VEGF and VEGF resulted in extensive angiogenesis and cyst formation when delivered in the ovary. However, unlike VEGF, EG-VEGF failed to promote angiogenesis in the cornea or skeletal muscle. Expression of human EG-VEGF messenger RNA is restricted to the steroidogenic glands, ovary, testis, adrenal and placenta and is often complementary to the expression of VEGF, suggesting that these molecules function in a coordinated manner. EG-VEGF is an example of a class of highly specific mitogens that act to regulate proliferation and differentiation of the vascular endothelium in a tissue-specific manner.     

Haemodynamic shear stress activates a K+ current in vascular endothelial cells

The endothelial lining of blood vessels is subjected to a wide range of haemodynamically-generated shear-stress forces throughout the vascular system. In vivo and in vitro, endothelial cells change their morphology and biochemistry in response to shear stress in a force- and time-dependent way, or when a critical threshold is exceeded. The initial stimulus-response coupling mechanisms have not been identified, however. Recently, Lansman et al. described stretch-activated ion channels in endothelial cells and suggested that they could be involved in the response to mechanical forces generated by blood flow. The channels were relatively nonselective and were opened by membrane stretching induced by suction. Here we report whole-cell patch-clamp recordings of single arterial endothelial cells exposed to controlled levels of laminar shear stress in capillary flow tubes. A K+ selective, shear-stress-activated ionic current (designated Ik.s) was identified which is unlike previously described stretch-activated currents. Ik.s varies in magnitude and duration as a function of shear stress (half-maximal effect at 0.70 dyn cm-2), desensitizes slowly and recovers rapidly and fully on cessation of flow. Ik.s activity represents the earliest and fastest stimulus-response coupling of haemodynamic forces to endothelial cells yet found. We suggest that localized flow-activated hyperpolarization of endothelium involving Ik.s may participate in the regulation of vascular tone.     

冲击波对肺血管内皮细胞通透性影响的机制

采用不同压力梯度爆炸冲击波对培养单层肺微血管内皮细胞滤膜作用的模型，观察了不同压力梯度爆炸冲击波对培养的肺微血管内皮细胞单层通透性的影响，并从一般病理学与细胞骨架结构角度探讨了冲击波作用下内皮通透性变化的可能机制。结果表明，电导法测定时，100kPa左右的爆炸冲击波压力作用即可见到单层内皮通透性的显著增加；350kPa以下的爆炸冲击波损伤主要以内皮细胞间隙的增加为主要类型，而600kPa以上的爆炸冲击波损伤，则主要以内此细胞的脱落性损伤为主。爆炸冲击波作用下内皮通透性变化的发生机制与细胞骨架肌球蛋白结构的变化有关。     

结直肠癌细胞过表达tricellulin促进人脐静脉内皮细胞侵袭转移

三细胞间紧密连接蛋白tricellulin在结直肠癌组织中高表达,且与结直肠癌的不良预后相关。血管生成是肿瘤侵袭转移的重要因素之一,血管内皮细胞在血管新生过程中起决定作用。研究tricellulin与内皮细胞的关系对探索肿瘤侵袭转移机制具有重要意义。本研究通过western blot观察结直肠癌细胞株与正常结肠上皮细胞株中tricellulin的差异表达,通过基因工程技术调控结直肠癌细胞HCT116中tricellulin的表达,transwell小室检测过表达tricellulin前后结直肠癌细胞侵袭能力变化及其上清液对人脐静脉内皮细胞（HUVEC）侵袭能力的影响,ELISA实验检测过表达tricellulin前后MMP2、MMP7的表达变化。结果显示：过表达tricellulin可增强HCT116细胞的侵袭能力,并且其上清液可增强HUVEC细胞的侵袭能力;过表达tricellulin可增加MMP2、MMP7的表达。说明人结直肠癌细胞过表达tricellulin可促进结直肠癌细胞侵袭迁移,并通过影响MMP2、MMP7的表达调控HUVEC细胞的侵袭转移。     

软骨血管生成抑制因子抑制血管生成及其抗肿瘤作用的研究

测定了小牛软骨血管生成抑制因子对血管内皮细胞细胞毒作用,对内皮细胞骨架系统及其运动迁移的抑制效应,对小鼠肿瘤生长的对抑制效应。     

Proliferation and differentiation into endothelial cells of human bone marrow mesenchymal stem cells （MSCs） on poly DL-lactic-co-glycolic acid （PLGA） films

Autologous, allograft and synthetic vessels currently used in clinical vessel replacement have many defi- ciencies, especially in the area of small caliber vessel replacement. The supply of autologous arteries or veins may not be sufficient or suitable fo…     

Astrocytes induce blood-brain barrier properties in endothelial cells

The highly impermeable tight junctions between endothelial cells forming the capillaries and venules in the central nervous system (CNS) of higher vertebrates are thought to be responsible for the blood-brain barrier that impedes the passive diffusion of solutes from the blood into the extracellular space of the CNS. The ability of CNS endothelial cells to form a blood-brain barrier is not intrinsic to these cells but instead is induced by the CNS environment: Stewart and Wiley demonstrated that when avascular tissue from 3-day-old quail brain is transplanted into the coelomic cavity of chick embryos, the chick endothelial cells that vascularize the quail brain grafts form a competent blood-brain barrier; on the other hand, when avascular embryonic quail coelomic grafts are transplanted into embryonic chick brain, the chick endothelial cells that invade the mesenchymal tissue grafts form leaky capillaries and venules. It is, however, not known which cells in the CNS are responsible for inducing endothelial cells to form the tight junctions characteristic of the blood-brain barrier. Astrocytes are the most likely candidates since their processes form endfeet that collectively surround CNS microvessels. In this report we provide direct evidence that astrocytes are capable of inducing blood-brain barrier properties in non-neural endothelial cells in vivo.     

Expression of an insulin-regulatable glucose carrier in muscle and fat endothelial cells

Insulin rapidly stimulates glucose use in the major target tissues, muscle and fat, by modulating a tissue-specific glucose transporter isoform. Access of glucose to the target tissue is restricted by endothelial cells which line the walls of nonfenestrated capillaries of fat and muscle. Thus, we examined whether the capillary endothelial cells are actively involved in the modulation of glucose availability by these tissues. We report here the abundant expression of the muscle/fat glucose transporter isoform in endothelial cells, using an immunocytochemical analysis with a monoclonal antibody specific for this isoform. This expression is restricted to endothelial cells from the major insulin target tissues, and it is not detected in brain and liver where insulin does not activate glucose transport. The expression of the muscle/fat transporter isoform in endothelial cells is significantly greater than in the neighbouring muscle and fat cells. Following administration of insulin to animals in vivo, there occurs a rapid increase in the number of muscle/fat transporters present in the lumenal plasma membrane of the capillary endothelial cells. These results document that insulin promotes the translocation of the muscle/fat glucose transporter in endothelial cells. It is therefore likely that endothelial cells play an important role in the regulation of glucose use by the major insulin target tissues in normal and diseased states.     

Induction of human vascular endothelial stress fibres by fluid shear stress

Endothelial cells of the arterial vascular system and the heart contain straight actin filament bundles, of which there are few, if any, in the venous endothelium. Since stress fibre-containing endothelial cells within the vascular system tend to be located at sites exposed to particularly high shear stress of blood flow, we have investigated, in an experimental rheological system (Fig. 1), the response of the endothelial actin filament skeleton to controlled levels of fluid shear stress. Here we report that endothelial stress fibres can be induced by a 3-h exposure of confluent monolayer cultures of human vascular endothelium to a fluid shear stress of 2 dynes cm-2, approximately the stress occurring in human arteries in vivo. Fourfold lower levels of shear stress that normally occur only in veins, had no significant effect on the endothelial actin filament system. The formation of endothelial stress fibres in response to critical levels of fluid shear stress is probably a functionally important mechanism that protects the endothelium from hydrodynamic injury and detachment.