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1.
乙酰胆碱对培养T细胞功能的作用   总被引:6,自引:0,他引:6  
邱一华  彭聿平 《生理学报》1995,47(3):275-280
本文研究不同浓度(10^-10-10^-4mol/L)乙酰胆碱(ACh)对离体培养的大鼠脾脏T淋巴细胞增殖的影响,并探讨其作用机制。实验结果表明:10^-9-10^-4mol/L可显著增强T细胞由刀豆素A(C-A)诱导的增殖反应,以10^-7-10^-6mol/L时最强。淋巴细胞先用ACh刺激1h或者刺激1h后洗弃ACh,再用ConA诱导6h的T细胞的增殖。10^-7-10-6mol/L阿托品可阻  相似文献   

2.
Zheng HZ  An GS  Nie SH  Tang CS  Liu NK  Wang SH 《生理学报》1998,50(4):379-384
培养的家兔胸主动脉血管平滑肌细胞(VSMC)分别以内皮素(ET-1)、一氧化氮(NO)前体L-Arg和NO供体SIN-1刺激,或用ET-1+L-Arg、ET-1+SIN-1联合刺激,测VSMC^3H-TdR掺入、丝裂素活化蛋白激酶(MAPK)活性及蛋白激酶C(PKC)活性的改变,以研究NO抑制ET-1促VSMC增殖作用的信号转导途径。结果表明:(1)ET-1 10^-8mol/L单独刺激,^3H-  相似文献   

3.
乙酰胆碱对大鼠体外抗体生成的影响   总被引:1,自引:1,他引:1  
目的:观察不同浓度乙酰胆碱(ACh,10-10~10-5mol/L)对大鼠体外抗体生成的影响,并初步探讨其作用机制,从细胞水平了解乙酰胆碱与免疫功能之间的关系。方法:用体外抗体生成的检测方法,用绵羊红细胞(SRBC)刺激大鼠肠系膜淋巴结B细胞转化成抗体形成细胞(AFC),然后检测其抗体生成量。结果:①10-10~10-7mol/LACh能显著抑制体外抗体生成,其中10-8和10-7mol/LACh的作用较强,而10-6和10-5mol/LACh无明显的抑制作用;②M型胆碱能受体激动剂毛果芸香碱(10-8和10-7mol/L)能明显减弱体外抗体生成,而N型受体激动剂烟碱(10-8和10-7mol/L)没有显著的减弱作用,M型受体拮抗剂阿托品(10-7和10-6mol/L)可完全阻断ACh抑制体外抗体生成的作用;③ACh分别在B细胞用SRBC刺激后3~48h中的6个不同时间与淋巴细胞作用,其抗体生成仍然是减少的。结论:ACh可非浓度依赖性地抑制大鼠的体外抗体生成;此作用可能由B细胞上的M型胆碱能受体介导;且ACh可能主要影响B细胞转化的后期过程。  相似文献   

4.
内皮素—1对大鼠排卵前卵泡颗粒细胞产生孕酮的影响   总被引:6,自引:1,他引:6  
本文用离体细胞体外孵育法研究了内皮素-1(ET)对大鼠排卵前卵泡颗粒细胞孕酮生成的影响及其作用机理。结果发现,ET能显著抑制hCG刺激下的孕酮产生,抑制作用在浓度为10-8mol/L时,即有显著意义(P<0.05,n=6),至10-7mol/L时则有非常显著的意义(P<0.01,n=6);不同浓度ET(10-7—10-7mol/L),对颗粒细胞基础孕酮的产生无明显影响。进一步研究表明,ET对hCG刺激下孕酮生成的抑制作用,在用免抗人内皮素抗血清(ET-A)1:1000及cAMP后能明显被逆转。实验中还观察到,ET使颗粒细胞LH/hCG受体数下降,亲和力降低。本文结果提示,ET可能为卵巢内的一种局部调节肽,通过作用于ET受体,干扰LH/hCG受体功能和cAMP生成而抑制颗粒细胞孕酮的产生。  相似文献   

5.
唐美仪  焦丽红 《动物学报》1999,45(3):323-331
为探讨人早期胎盘组织产生的促肾上腺皮质激素释放激素(CRH)的生物学作用及其绒毛膜促性腺激素(hCG)合成和释放的调控机制,在人早期胎盘组织体外孵育模型上研究了CRH及其拮抗剂(α-HelicalCRF9-41)对hCG基础分泌和由GnRH刺激的hCG分泌的影响。结果表明,10^-10 ̄10^-7mol/L的外源性CRH可明显抑制hCG的基础释放,而以10^-7mol/L作用最显著;加入10^=-  相似文献   

6.
在Con A和固相抗CD3单抗刺激系统中,应用抗LFA-1/ICAM-1单抗,研究其在胸腺细胞活化中的功能作用,结果证明,培养初期加入可溶性抗LFA-1可完全阻断Con A活化腺细胞增殖,对固相抗CD3单抗诱导的胸腺细胞活化也表现也相同的抑制效应,但对Con A刺激24h后的胸腺细胞应答以及IL-1+IL-2诱导的胸腺细胞直殖无影响,在可溶性抗LFA-1单抗的存在下,Con A诱导胸腺细胞合成IL  相似文献   

7.
人绒毛膜促性腺激素β—亚基在中国仓鼠卵巢细胞中…   总被引:4,自引:0,他引:4  
本文以哺乳动物细胞表达载体pSV2-dhfr为运载体,构建了受控于SV40早期启动子β-hCG基因的表达载体,转染CHO-hfr^-细胞后,挑选CHO(dhfr^+)细胞,结果表明β-hCG不仅在细胞中表达,不分泌到培养液中,通过氨甲喋(MTX)加压后,表达量逐渐提高,0.1μmol/LMTX条件下培养液中β-hCG最高表达量可达到1.5μg/10^6细胞.24小时。经亲和层析获得纯的重组β-hC  相似文献   

8.
抗旱性不同的两个大豆品种对外源H2O2的响应   总被引:17,自引:0,他引:17  
两个品种的大豆叶圆片经10^-4mol/L和10^-3mol/L的H2O2处理12h后,超氧化岐化酶(SOD)、过氧化氢酶(CAT)与谷胱甘肽还原酶(GR)活性明显增加,但10^-2mol/L的H2O2处理却使这些酶活性降低。抗旱性较强的大豆品种小粒豆1号较抗旱性较弱的鲁豆4号能维持较高的叶绿素含量和较高的SOD、CAT及GR活性,对H2O2的抗性较强。50μmol/L的亚胺环已酮(CHM)能消除  相似文献   

9.
LFA—1/ICAM—1在ConA诱导的小鼠胸腺细胞活化中的作用   总被引:1,自引:1,他引:0  
用抗LFA-1/ICAM-1粘附分子单克隆抗体和ConA联合刺激小鼠胸腺细胞,初步研究了该膜分子在经TCR/CD3介导的胸腺细胞活化信号传导以及胸腺细胞亚群选择中的作用。在ConA刺激系统中,抗ALFA-1/ICAM-1单抗均能抑制胸腺细胞的增殖应答,且以抗LFA-1单抗均能抑制胸腺细胞的增殖应答,且以抗LFA-1单抗的作用更为显著,而在PAM加钙离子载体A23187刺激体系中,抗LFA-1单抗却  相似文献   

10.
目的和方法:本研究采用全细胞膜片箝技术,观察皮质酮(B)对PC12细胞上乙酰胆碱诱发电流(IACh)的快速作用并初步探讨其可能机制。结果:PC12细胞上IACh是通过烟碱受体(nAChR)引起的。箝制电压为-80mV时,ACh(30μmol/L)诱发一内向电流;细胞外灌流同时给予ACh和B(10-5mol/L)时,B对IACh的抑制作用较弱;用B(10-5mol/L)对细胞进行预处理,可提高B对IACh峰值的抑制率,作用呈可逆性、浓度依赖性和非电压依赖性;细胞外用RNA合成抑制剂放线菌素D(4×10-5~4×10-3mol/L)或蛋白合成抑制剂放线菌酮(10-4~10-3mol/L)孵育细胞1~2h阻断基因机制,但均不影响B对IACh的快速抑制作用。结论:B对PC12细胞上IACh有快速抑制作用,此作用可能是由非基因组机制介导的。  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   

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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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