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1.
应用细胞内记录,研究了豚鼠腹腔神经节(CG)细胞非胆碱能迟慢兴奋性突触后电位(LS-EPSP)与5-羟色胺(5-HT)及P物质(SP)的相互关系。当重复电刺激内脏大神经(SN)时,有78.2%的细胞(161/206)在动作电位发放后出现LS-EPSP,灌注或压力注射5-HT或SP,分别在68.5%的细胞(102/149)及52.1%的细胞(98/188)上引起5-HT或SP去极化反应,两者差异非常显著(P<0.01);大部分具有LS-EPSP的细胞对5-HT(73/88,83.0%)或SP(68/11459.6%)敏感,而不出现LS-EPSP的细胞仅有少数对5-HT(10/26,38.5%)或SP(11/36,30.6%)敏感,两类细胞的差异非常显著(5-HT:P<0.0001,SP:P<0.01)。上述结果支持5-HT与SP均作为递质参与LS-EPSP形成的观点。此外,在133个细胞上同时检测了5-HT与SP的作用,其中有66个细胞(49.6%)对5-HT及SP均敏感,提示在CG细胞,5-HT与SP之间可能存在某种机能联系。  相似文献   

2.
裴文芬  祝延 《生理学报》1996,48(3):263-268
应用细胞内记录,研究了豚鼠腹腔神经节细胞非胆碱能迟慢兴奋性突触后电位与5-羟色胺及P物质的相互关系。当重复电刺激内脏大神经时,有78.2%的细胞在动作电位发放后出现LS-EPSP;灌注或压力注射5-HT或SP,分别在68.5%的细胞(102/149)及52.1%的细胞(98/188)上引起5-HT或SP去极化反应,两者差异非常显著(P〈0.01);大部分具有LS-EPSP的细胞对5-HT(73/8  相似文献   

3.
5—羟色胺对肺动脉平滑肌细胞在缺氧条件下增殖的作用   总被引:2,自引:1,他引:1  
刘健  王培勇 《生理学报》1997,49(3):292-298
本研究应用细胞培养、^3H-TdR掺入,核酸分子杂交、免疫组织化学染色技术,探讨无氧(0%O2+95%N2+5%CO2)和/或低氧(2.5 ̄3%O2+92%N2+5%CO2)对新生小牛肺动脉平滑肌细胞增殖和5-羟色胺转载体基因表达的影响。结果表明:无氧24h可刺激PASM的DNA合成,^3H-TdR的掺入增加(P〈0.05),加入5-羟色胺能非常显著地促进无氧PASM增殖(P〈0.001),而对常  相似文献   

4.
用酸碱法从而包酵母中提取β——(1——3)——D葡聚糖   总被引:8,自引:0,他引:8  
研究了用酸-碱法制备水不溶性葡聚糖的工艺。0.75mol/L的NaOH在100℃作用2h,能有效地去除甘露聚糖,0.5mol/L的酸使不溶性的葡聚糖的比粘度增加,除去糖元,分析表明,产品为β-D-葡聚糖,其中β-(1-3)-D-葡聚糖约为87%。  相似文献   

5.
NA和5-HT对小脑脑片浦肯野细胞自发及诱发电活动的影响   总被引:2,自引:0,他引:2  
在大鼠小脑脑片上观察了NA和5-HT对浦肯野细胞(PC)的自发放电活动及由白质刺激所引起的诱发放电活动的影响。结果表明:(1)NA使PC产生抑制、兴奋和双相反应,以抑制反应为主(79.8%);5-HT引起PC兴奋和抑制反应,以兴奋反应略多(57.8%)。(2)先后灌流NA和5-HT对同一个PC自发放电的影响主要为抑制(NA)-兴奋(5-HT)(53.8%)。(3)NA对PC的诱发复杂锋电位(CS)和简单锋电位(SS)反应,主要产生增强效应(57.1%和62.8%);5-HT对PC诱发CS和SS反应则主要产生压抑作用(60.0%和68.2%)。(4)先后灌流NA和5-HT对同一个PC的诱发CS和SS反应,主要表现为NA对这两种诱发反应的增强和5-HT的压抑效应(60.0%和52.9%)。这些结果提示,NA能和5-HT能传入纤维可以通过释放NA和5-HT调节PC的兴奋性水平并改变PC对爬行纤维和苦状纤维突触传入的反应敏感性,影响小脑皮层神经元网络的感觉运动整合过程。  相似文献   

6.
褪黑素对大鼠海马神经元谷氨酸所致毒性的拮抗作用   总被引:3,自引:0,他引:3  
在大鼠海马脑片上电刺激Schaffer 侧支纤维, 胞外记录CA1 区锥体细胞层诱发群体锋电位(population spike,PS) , 观察灌流谷氨酸(Glu) 和褪黑素(MEL) 对PS的影响。结果显示:5-0 mmol/L浓度的Glu 可使PS值下降至对照值的4-1 % ; MEL(0-4 、0-5 和0-6 μmol/L) 与5-0 mmol/LGlu 混合给药,PS值分别变化为对照值的14-7 % 、105-2% 、24-3 % ; MEL(0-5 μmol/L) 、Glu (5-0 mmol/L) , 与赛庚啶(CDP,0-5 μmol/L) 混合给药,PS值下降至0 。上述结果提示,5-0 mmol/L浓度的Glu 有神经毒性作用, 但可为MEL拮抗, 这可能由5HT受体所介导。  相似文献   

7.
微生物木聚糖降解酶研究进展及应用前景   总被引:32,自引:0,他引:32  
木聚糖是植物半纤维素的主要成分,它是除纤维素外,自然界中最为丰富的多糖。木聚糖的基本结构单元是由β-1.4或β-1.3糖苷键连接的多聚木糖链,在D-木糖的第二位氧上连接有D-葡萄糖醛酸或4-O-甲基葡萄糖醛酸或在第三位氧上连接有L-阿拉伯呋喃糖。有些木聚糖还在第二或第三位氧上发生乙酰化。不同来源的木聚糖在结构上有一定差异。木聚糖酶是一类木聚糖降解酶系(表1),对降解自然界大量存在的半纤维素起着重要作用。它们不但可以降解木聚糖生成木糖,而且能以农作物残渣中的半纤维素为原料生产经济价值较高的产品。由…  相似文献   

8.
在74张大鼠下丘脑脑片上,用玻璃微电极记录到弓状核自发放电单位176个,其放电形式有三种:慢不规则型(119个,67.6%);快连续型(46个,26.1%);位相型(11个,6.3%)。5-HT(10-6mol/L,3min)对不同形式放电单位的作用均以抑制为主:对部分慢不规则单位(9/119)则表现为先抑制后兴奋的双相性反应,对少数神经元有兴奋作用。12个被5-HT抑制的单位,其抑制作用不能被噻庚啶(CHD,10-5mol/L)阻断,4个被5-HT抑制的的单位中,其抑制作用可被二甲基麦角新碱(MSG10-6mol/L)部分或完全阻断。7个被5-HT抑制的单位,其中4个单位中,5-HT的抑制作用可被特异性5-HT1A受体阻断剂Pindobind-5-HT1A部分阻断;但另外3个单位的阻断效果不明显。上述结果表明:5-HT对弓状核不同形式放电单位的作用均以抑制为主,其作用可能是通过5-羟色胺(5-HT1)受体介导的,部分还可能是通过5-HT1A受体介导的。  相似文献   

9.
胡卫红  王建军 《生理学报》1996,48(6):581-586
在大鼠小脑脑片上观察了NA和5-HT地浦背野细胞(PC)的自发放电活动及由白质刺激所引诱发放电活动的影响。结果表明:(1)NA使PC产生抑制、兴奋和双相反应,以抑制反应为主(79.8%);5-HT引起PC兴奋和抑制反应,以兴奋反应略多(57.8%)。(2)先后灌流NA和5-HT对同一个PC自发放电的影响主要为抑制(NA)-兴奋(5-HT)(53.8%)。(3)NA地PC的诱发复杂锋电位(CS)和简  相似文献   

10.
以遗传性脊髓小脑共济失调Ⅱ型基因(spinocerebellar ataxia typeⅡgeneSCA2)编码区内的CAG三核苷酸重复为研究对象(G+C含量为69.2%),比较了热启动PCR、碱基替代PCR、添加增效剂(1%-12.5%二甲亚砜、1%-25%甘油、1%-12.5%甲酰胺)与常规PCR的扩增效率,发现热启动PCR、碱基替代PCR及添加增效剂(1%-10%二甲亚砜、5%-20%甘油、  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   

18.
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   

19.
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   

20.
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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