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1.
目的:探讨双环醇(bicyclol)对超氧阴离子(O2)诱导的血管舒张功能损伤的影响。方法:采用离体器官灌流技术,观察bicyclol对离体大鼠胸主动脉环张力的影响。采用焦酚(O2的供体)建立O2损伤模型,观察bicyclol预孵育对氧化应激损伤后血管内皮依赖性舒张功能的改善作用。结果:bicyclol(10-8~10-5mol/L)对由苯肾上腺素预收缩的内皮完整主动脉环产生舒张作用,该作用可被NO合酶抑制剂L-NAME和环氧化酶抑制剂吲哚美辛阻断。500μmol/L焦酚可引起乙酰胆碱诱导的主动脉环内皮依赖性舒张反应减弱,bicyclol(10-5mol/L)预孵育45 min可减轻焦酚的损伤作用。对于吲哚美辛处理的主动脉环,bicyclol(10-5mol/L)可抑制焦酚所致的血管舒张反应降低,但这一效应未见于L-NAME处理的主动脉环。结论:bicyclol具有内皮依赖性舒血管作用,并能对抗O2引起的血管舒张功能损伤,该作用通过NO途径介导。  相似文献   

2.
白细胞介素-2引起离体大鼠主动脉环舒张及其作用机制   总被引:20,自引:2,他引:18  
Cao CM  Ye S  Yu H  Xu QS  Ye ZG  Shen YL  Lu Y  Xia Q 《生理学报》2003,55(1):19-23
本文旨在研究白细胞介素-2(interleukin-2,IL-2)以离体大鼠胸主动脉环收缩张力的作用及其可能机制。采用累积加药法,检测IL-2对去氧肾上腺素(PE)和KCl预收缩的胸主动脉环收缩张力的影响。结果表明,IL-2(1、10、100、1000U/ml)对PE(10μmol/L)预收缩的内皮完整血管环产生浓度依赖性的舒张作用,而对KCl (120mmol/L)预收缩的血管无作用,去除内皮后,IL-2的舒张作用被取消。用一氧化氮合酶抑制剂L-NAME(0.1mmol/L)和鸟苷酸环化酶抑制剂亚甲蓝(10μmol/L)预处理,均可阻断IL-2的舒张血管作用。用环氧合酶抑制剂吲哚美辛(Indo,10μmol/L)预处理可阻断IL-2的血管舒张作用。从上述观察结果推论,IL-2通过NO-鸟苷酸环化酶和环氧合酶途径产生内皮依赖的血管舒张作用。  相似文献   

3.
乙醇对离体大鼠胸主动脉环的舒张作用及其机制   总被引:1,自引:0,他引:1  
目的:观察不同预张力下乙醇对离体大鼠胸主动脉环舒缩作用的影响及其机制.方法:采用离体血管灌流技术,设置不同预张力,记录乙醇作用下离体大鼠胸主动脉环的张力变化.结果:不同预张力下(1.0、1.5、2.0、2.5、3.0、3.5、4.0 g),乙醇(0.1‰、0.2‰、0.5‰、0.8‰、1.5‰、3.0‰、7.0‰.)对由KCl(6×10-2mol/L)或苯肾上腺素(phenylephrine,PE,10-6mol/L)预收缩的去内皮血管环产生舒张作用,其中3 g预张力下乙醇舒血管作用最明显;但对内皮完整血管环的舒张作用较弱;在3 g预张力下,最大效应浓度(3‰)的乙醇可使由KCl或PE预收缩的去内皮血管环的CaCl2量效曲线下移,最大反应显著降低:在3 g预张力下,肌浆网ryanodine受体阻断剂钌红(10-5mol/L)及三磷酸肌醇(trisphosphate inositol,IP3)受体阻断剂肝素(50 mg/L)预孵育可减弱乙醇对由PE预收缩的去内皮血管环的舒张作用.结论:乙醇具有不依赖内皮的舒血管作用,3 g预张力下舒血管作用最强.乙醇可能通过抑制血管平滑肌细胞膜上电压依从性和受体操作性钙通道,减少外钙内流,以及抑制肌浆网ryanodine受体和IP3受体途径,减少内钙释放而发挥舒血管作用.  相似文献   

4.
Apelin对大鼠离体肺动脉环的舒张作用及与一氧化氮的关系   总被引:1,自引:0,他引:1  
目的:探讨新的小分子活性肽Apelin对大鼠离体肺动脉环的舒张作用及与一氧化氮(NO)途径的关系,并比较低氧大鼠的肺动脉环对Apelin的舒张反应与正常大鼠的差异。方法:36只大鼠随机分为正常组与低氧组;采用离体血管环灌流法,检测Apelin对去甲肾上腺素(NE)预收缩的大鼠离体肺主动脉环的舒张效应,观察去内皮或用一氧化氮合酶抑制剂(L-NAME)、可溶性鸟苷酸环化酶(sGC)抑制剂(ODQ)孵育后该舒张率的变化。结果:①在正常组大鼠肺动脉环,Apelin(0.01~100 nmol/L)具有浓度依赖性的舒张效应。去除内皮后,Apelin对NE预先收缩的肺血管舒张效应明显减弱(P〈0.01)。L-NAME或ODQ预孵育后,Apelin的舒张效应均明显减弱(P均〈0.01)。②低氧组大鼠的肺动脉环对Apelin的舒张反应明显低于正常组大鼠,在最大浓度100 nmol/L时,Apelin的效应低60.45%(P〈0.01),而两组EC50相比差异无显著性(P〉0.05)。结论:Apelin具有内皮依赖性的舒张肺动脉环的作用,该效应与NO-sGC-cGMP信号途径有关;低氧大鼠的离体肺动脉环对Apelin的舒张反应减弱。  相似文献   

5.
Liu SQ  Zang WJ  Li ZL  Sun Q  Yu XJ  Luo HL  Zhu SM 《生理学报》2005,57(1):21-26
研究显示,山莨菪碱预处理不改变高钾引起的兔主动脉环收缩,但可明显减弱去甲肾上腺素(noradrenaline,NA)、组织胺或5-羟色胺引起的收缩,且其减弱作用不受去除血管内皮影响。本实验观察了几种钾通道阻断剂对山良菪碱松弛:NA预收缩的兔主动脉环的影响。结果表明,1、3、10μmol/L山莨菪碱作用8min,可使0.01μmol/L NA预收缩的兔主动脉环松弛(P<O.01)。10mmol/L,CsCl、1mmol/L 4-氨基吡啶、10μmol/L BaCl2、10μmol/L格列本脲、3μmol/L charybdotoxin和3μmol/L蜂毒明从分别与0.0lμmol/L NA同时加入,可增强后者收缩兔主动脉环的作用(P<0.01)。10、30mmol/L CsCl或10、30mmol/L 4-氨基吡啶存在时,10μmol/L山茛菪碱对NA预收缩的兔主动脉环的松弛作用减弱,松弛率与对照组比较分别有极显著差异(P<0.01);10、30μmol/L BaCl2,10、30μmol/L格列本脲,3μmol/L charybdotoxin或3μmol/L蜂毒明肽存在时,山莨菪碱对NA预收缩的兔主动脉环的松弛作用不受影响(P>O.05)。本研究表明,电压激活的钾通道阻断剂抑制山莨菪碱松弛NA预收缩的兔主动脉平滑肌,初步提示血管平滑肌细胞膜上电压激活的钾通道参与山莨菪碱扩血管作用。  相似文献   

6.
为了观察槲皮素对大鼠离体肾动脉的舒张作用,并探讨该作用与蛋白激酶C(protein kinase C,PKC)的关系,本研究采用血管张力测定仪记录大鼠肾动脉肌张力变化,用膜片钳全细胞记录方式记录大鼠肾动脉血管平滑肌细胞(vascular smooth muscle cell,VSMC)L-型电压依赖性钙通道(L-type voltage-gated Ca~(2+) channels,LVGC)电流。实验结果显示,槲皮素能够舒张60 mmol/L KCl或1×10~(-5) mol/L苯肾上腺素(phenylephrine,PE)预收缩的大鼠肾动脉,其最大舒张百分比分别为(84.53±7.35)%和(76.42±4.63)%;血管内皮完整组和去内皮组肾动脉相比,槲皮素对预收缩肾动脉的最大舒张百分比没有显著性差异;预孵育PKC特异性抑制剂C6303可使槲皮素对肾动脉的最大舒张幅度降低,与未孵育C6303组相比具有统计学差异(P0.05);离体大鼠肾动脉VSMC的正常LVGC尖峰电流密度为(23.17±1.33)pA/pF,10μmol/L槲皮素可以降低其电流密度到(10.46±1.35)pA/pF,其抑制百分比为54.86%,1μmol/L C6303可部分逆转槲皮素对LVGC电流的降低幅度,其抑制百分比为62.08%(P0.05)。上述实验结果提示,槲皮素可舒张大鼠离体肾动脉,该作用具有浓度依赖性且不受内皮影响,可能与抑制LVGC和激活PKC有关。  相似文献   

7.
目的:探讨植物雌激素美皂异黄酮舒张血管的可能机制。方法:采用MedLab生物信号采集系统记录灌流大鼠胸主动脉环张力变化。结果:美皂异黄酮(10-9~10-4mol/L)对苯肾上腺素(PE,10-5mol/L)预收缩的内皮完整或去内皮血管环均产生浓度依赖性的舒张作用;美皂异黄酮对高浓度氯化钾(KCl,6×10-2mol/L)预收缩的血管环也产生浓度依赖性的舒张作用;四乙胺(TEA,5×10-3mol/L)或格列苯脲(3×10-6mol/L)预处理对美皂异黄酮诱导的去内皮动脉环舒张作用具有明显的抑制效应;在无钙液中,美皂异黄酮抑制PE引起的去内皮主动脉环的短暂收缩。结论:美皂异黄酮的非内皮依赖性血管舒张作用的机制可能涉及血管平滑肌细胞的Ca2+激活K+通道和ATP敏感性K+通道的激活,以及肌浆网内钙离子释放的减少。  相似文献   

8.
目的:研究葡萄籽中原花青素(PA)对大鼠离体主动脉平滑肌收缩活动和兔血小板聚集的影响.方法:采用大鼠离体主动脉环灌流方法,记录主动脉环张力变化,观察PA对去甲肾上腺素(NA)和KCl预收缩大鼠离体主动脉平滑肌收缩反应的舒张作用以及对NA量效曲线的影响.比浊法测定兔血小板聚集.结果:PA能明显抑制NA(10-6mol/L)预收缩大鼠离体主动脉环的反应,使NA量效曲线压低,最大反应降低,此作用无内皮依赖性,但对KCl预收缩主动脉环的舒张作用无明显影响,也不影响花生四烯酸(AA),ADP和胶原(collagen)蛋白诱导的兔血小板聚集.结论:PA能对抗NA而不影响KCl诱导的大鼠离体主动脉平滑肌的收缩,不影响兔血小板聚集.  相似文献   

9.
制备离体大鼠胸主动脉环,分有内皮组和去内皮组,采用离体血管灌流技术,观察胰岛素对去氧肾上腺素(PE)和氯化钾(KCl)预收缩的胸主动脉环收缩张力的影响。结果表明胰岛素对PE预收缩的胸主动脉环产生浓度依赖性的舒张作用,且有内皮组和去内皮组间无显著差异。胰岛素对KCl预收缩的胸主动脉环没有显著影响。胰岛素对PE预收缩的胸主动脉环有非内皮依赖性舒张作用。  相似文献   

10.
胍丁胺对离体大鼠主动脉张力的影响及其受体机制   总被引:2,自引:1,他引:1  
Li Q  He RR 《生理学报》2001,53(2):133-136
采用离体血管环灌流方法,观察了胍丁胺(agmatine,Agm)对大鼠胸主动脉张力的影响,并探讨其受体机制,实验结果如下:(1)在苯肾上腺素PE,10^-6mol/L)引起血管预收缩的 基础上,Agm(10^-7-10^-2mol/L)剂量依赖性地舒张大鼠胸主动脉。(2)上述舒张反应在去除内皮和应用NOS抑制剂N^-G-mnitro-L-arginine methyl ester(L-NAME,0.5mmol/L)后依然存在,提示Agm的舒血管作用为非内皮依赖性,并无NO的参与。(3)在高Ca^2 (3mmol/L)引起血管预收缩的基础上,Agm也可剂量依赖性地舒张大鼠主动脉。(4)预先应用α2-肾上腺素能受体(α2-adrenergic receptor,α2-AR)和咪唑啉受体(IR)阻断剂idazoxan(10^-4mol/L)则可完全阻断Agm的上述作用。(5)应用α2-AR拮抗剂yohimbine(10^-4mol/L)可部分阻断Agm对大鼠主动脉的舒张反应,以上结果表明,Agm对大鼠主动脉血管的舒张作用是由α2-AR和IR共同介导。  相似文献   

11.
The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.  相似文献   

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Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

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The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

16.
2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3ai. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3ai were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities.  相似文献   

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Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.  相似文献   

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