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1.
缺氧对培养的肺动脉内皮细胞血管紧张素Ⅱ分泌的影响   总被引:2,自引:0,他引:2  
缺氧是否通过影响血管内皮细胞的分泌功能而参与缺氧性肺动脉高压的发生尚不清楚。本实验动态观察了缺氧对培养的新生小牛内皮细胞(PAEC)的血管紧张素Ⅱ(ATⅡ)分泌的影响。结果发现:2.5%O2缺氧早期(1.5h),PAEC的ATⅡ分泌增加(P<0.01vs常氧组),缺氧后期与常氧组无明显差别;0%O2缺氧早期(1.5-6h),ATⅡ分泌明显降低(P<0.01vs常氧组及2.5%O2组),后期ATⅡ分泌明显增高(P<0.01vs常氧组及2.5%O2组);无论缺氧还是常氧条件下,NO供体SIN1显著抑制ATⅡ的分泌(P<0.01),而内源性NO抑制剂硝基精氨酸则明显促进ATⅡ分泌(P<0.01);0%O2缺氧24h后,PAEC细胞内cGMP含量明显降低(P<0.05)。上述结果表明缺氧可通过抑制PAEC的内源性NO产生而促进ATⅡ的分泌,PAEC自分泌的改变可能参与缺氧性肺动脉高压的发生过程。  相似文献   

2.
目的和方法:将红细胞生成素(EPO)3'-增强子野生片断及点突变片断借脂质体主人脐静脉内皮细胞株ECV-304,用半定量RT-PCR测定正常秘缺氧诱导因子-1(HIF-1)诱导剂氧化钴(CoCl2)作用下培养6h的细胞环氧合酶2(COX-2)和血栓素合酶(TXS)的mRNA。结果:HIF-1诱导剂CoCl2可放COX-2和TXS基因转明显增强2,向细胞导入野生EPO3'增强子片断可阻断CoCl2诱  相似文献   

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本文利用Northern印迹分析技术研究了完全致癌物二甲基苯蒽(DMBA)对小鼠表皮鸟氨酸脱羧酶(ODC)mRNA和转化生长因子β(TGF-β)mRNA水平的影响。DMBA在15μg和900μg剂量下一次涂用于小鼠皮肤,可使表皮ODCmRNA和TGF-βmRNA表达增加。ODCmRNA为单一的2.0kb大小的条带,其表达在在36h时最为明显。而TGF-βmRNA大小为2.5kb和1.9kb,其表达在36h时最高,到48h几乎降至正常,但在72h又有增加。ODC和TGF-β可能在DMBA诱癌过程中起重要作用。  相似文献   

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通过培养的人主动脉平滑肌细胞(hASMC)及脐静脉内皮细胞(hUVEC),应用3H-TdR参入、Northernblot分析、逆转录多聚酶链反应(RT-PCR)、放射免疫分析(RIA)、和紫外比色法等技术观察了人主动脉中硫酸乙酰肝素蛋白聚糖(HSPG)对hASMC和hUVECDNA合成的作用及对血小板源生长因子(PDGF)、PDGF受体、转化生长因子β(TGF-β)、内皮素-1(ET-1)或碱性成纤维细胞生长因子(bFGF)基因表达和肾素-血管紧张系统(RAS)的影响,结果显示,HSPG明显抑制培养的hASMC基础的DNA合成(cpm值为:10385±3263vs,25541±6421,P<0.01)及外源性PDGF诱导的DNA合成(cpm值为:9878±1947vs.13481±44l0,P<0.05);抑制PDGFA链、TGF-Bp和ET-1mRNA表达,提高PDGFa和β受体mRNA的表达;显著降低hASMC培养液中血管紧张素Ⅱ(AngⅡ)的浓度和血管紧张素转换酶(ACE)的活性,推测HSPG抑制PDGFA链、TGF-β及ET-1mRNA表达,降低ACE活性及AngⅡ浓度是其抑制hASMC增殖的重要机  相似文献   

5.
牛磺酸调节缺氧性肺、脑血管反应的机理研究   总被引:9,自引:0,他引:9  
本实验从磷脂酶A_2(PLA_2)、前列腺素(PGs)、白三烯(LTs)和过氧化脂质(LPO)方面探讨了牛磺酸调节肺、脑血管对急、慢性缺氧反应的机制。急性缺氧时狗出肺与出脑血中LPO增加,PLA,活性有升高趋势,但出脑与出肺(入脑)血相比无显著性差异。出肺与出脑血中LTC_4、TXB_2、6-Keto-PGF_(1a)及TXB_2/6-Keto-PGF_(1a)比值均升高。慢性缺氧大鼠肺、脑组织中PLA_2活性均升高。牛磺酸增加缺氧时6-Keto-PGF_(1a),减弱其它变化。提示牛磺酸对缺氧性肺缩血管反应的调节作用可能与降低缺氧时PLA_2活性,抑制脂质过氧化和LTC_4、TXA_2生成,降低TXA_2/PGI_2比值有关;而牛磺酸减弱缺氧性脑舒血管反应不是直接通过上述变化起作用的。  相似文献   

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将bdnf基因克隆入逆转录病毒载体pLNCX,构建得到pLNC/BDNF,经PA317细胞包装后,感染大鼠成肌细胞L6TG,G418筛选2周后,得到稳定表达bdnf基因的细胞克隆L6TG/BDNF。DNA印迹结果证实bdnf基因已经整合入L6TG染色体中,RNA印迹和斑点印迹结果分别从mRNA水平和蛋白水平证明了bdnf基因的表达,且L6TG/BDNF培养上清中BDNF的含量约为25ng(106细胞数每ml每24h)。  相似文献   

7.
DDPH[1-(2.6-二甲基苯乙氧基)-2-(3.4二甲氧基苯乙胺基)丙烷盐酸盐]是南京药科大学合成的降压新化合物,也具有降低肺动脉高压和抑制肺动脉平滑肌细胞增殖作用。本实验用细胞培养、免疫细胞化学、图像分析、3H-TdR、细胞周期测定等方法,进一步探讨DDPH对缺氧性肺动脉平滑肌细胞(PASMCS)增殖的抑制机制。结果:缺氧促进肺动脉内皮细胞(PAECs)的PDGF·BB和bFGF两种生长因子的表达(积分光密度OD值)增高。缺氧内皮细胞条件培养液(HECCM)能促进PASMCS的PDGF·BB的OD值增高,bFGF的OD值无明显改变。加药组(HEC-CM+DDPH)的PDGF·BB和bFGF的OD值均显著降低,尤以PDGF·BB的OD值减少最多.提示:DDPH能抑制HECCM引起PASMCS的PDGF·BB和bFGF表达增多和细胞增殖。结果与大鼠实验观察相符。  相似文献   

8.
内毒素诱导兔肺动脉平滑肌iNOS生成中NF—κB作用的探讨   总被引:4,自引:0,他引:4  
目的和方法:实验采用内毒素的主要成分脂多糖(LPS)离体孵育去内皮兔肺动脉环方法,观察血管收缩性的改变,并加入诱生型NO生成抑制剂氨基胍(AG)以及核转录因子(NFκB)的拮抗剂吡咯烷二硫代氨基甲酸盐(PDTC)后观察了血管收缩性的变化。结果:LPS孵育16h后血管环对新福林(PE)的反应性明显减低(P<0.01),与LPS孵育组比较,LPS与AG共同孵育后血管环反应性增加,PDTC预孵育血管环后再用LPS孵育,血管环反应性也较LPS孵育的血管环反应明显增加。经LPS孵育的血管环用NO生成抑制剂L硝基精氨酸(LNNA)处理后,对血管收缩剂PE的反应性有明显增加,而PDTC预孵育组的血管环用LNNA处理后收缩反应性无明显增加。结论:LPS离体孵育去内皮肺动脉后,血管平滑肌iNOS诱生,致使血管反应性降低,而NFκB在肺动脉平滑肌iNOS诱生中起信息传递作用。  相似文献   

9.
中国山西,广西美芒藻属两新种   总被引:1,自引:0,他引:1  
中国山西、广西美芒藻属两新种谢树莲凌元洁(山西大学生命科学系太原030006)TWONEWSPECIESOFCOMPSOPOGON(RHODOPHYTA)FROMSHANXIANDGUANGXI,CHINAXIEShuLianLINGYuanJ...  相似文献   

10.
淡水红藻一新种——异孢奥杜藻   总被引:2,自引:0,他引:2  
淡水红藻一新种———异孢奥杜藻谢树莲凌元洁(山西大学生命科学系太原030006)ANEWSPECIESOFFRESHWATERREDALGAE———AUDOUINELLAHETEROSPORAFROMCHINAXIEShuLianLINGYuan...  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

16.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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