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1.
α受体激动对绵羊心肌瞬时性内向离子流的影响   总被引:1,自引:0,他引:1  
施渭彬  徐有秋 《生理学报》1995,47(4):387-393
用乙酰毒毛旋花子甙元(AS)0.05μmol/L诱发绵羊心浦肯野纤维产生稳定的瞬时性内向离子流(Iti),用普萘洛尔0.5μmol/L阻断β受体,观察α受体激动剂苯肾上腺素(PE)0.3,1.0μmol/L对Iti幅值与时程的影响。PE1.0μmol/L灌流20,50min时Iti幅值分别由对照值12.8±1.9nA减小至10.7±1.2nA(n=5,P<0.05)与9.6±1.9nA(n=5,P<0.01);ItiD50时程分别由对照值145±24.4ms延长至183.3±28.1ms(n=5,P<0.05)与207.5±34.2ms(n=5,P<0.01),PE对Iti的抑制作用呈剂量依赖性与时间依赖性。Iti到达峰值的时间和回复到基线的时间都延长,提示PE作用下Iti通道动力学发生了变化。如果在β受体激动剂异丙肾上腺素(ISO)1.0μmol/L增强Iti的基础上,PE1.0μmol/L灌流10min,对Iti幅值的抑制及时程的延长作用更显著,Iti幅值由对照值15.6±3.2nA减小到10.3±2.2nA;ItiD50由92.5±14.3ms延长到132.5±36.0ms(n=5,P<0.01)。  相似文献   

2.
正常小鼠高频心电图时域值和功率谱的研究   总被引:4,自引:1,他引:4  
本文用南京新博公司生产的NHE-1000型心电高频信息检测分析仪研究了正常小鼠(昆明种)高频心电图(HF-ECG)的时域值和QRS波群的功率谱。主要结果如下(以正导为例,-X±SD):心率603±88次/min(n=74);P-R间期相对较长。为34.9±4.7ms(n=58),占心动周期的34.9±4.9%,这与人类有很大的不同;QRS波宽9.2±1.2ms,占心动周期的9.2±1.4%(n=74),这一结果与以前的文献报道相差较大。T波宽10.3±3.2ms,占心动周期的10.3±3.2%;Q-T间期19.4±3.2ms,占心动周期的19.5±3.6%;QRS波群峰-峰值(Vp-p)为1.456±0.480mV;T波高0.336±0.115mV;73只动物Ⅱ导联高频切迹总数只有3个,扭挫26个。Ⅱ导联QRS波群的功率谱特点:0—80Hz的相对能量为45.48±15.32%;80—200Hz为43.97±9.95%;200—300Hz为8.89±7.38%;300—1000Hz为1.66±2.74%。  相似文献   

3.
SNP抑制5-HT诱导的胞内游离钙浓度升高和内钙释放   总被引:2,自引:0,他引:2  
用Fura - 2/AM 荧光测量技术研究了5 - 羟色胺(5- HT) 诱导的大鼠尾动脉平滑肌细胞胞内钙升高和一氧化氮(NO) 的抑制效应。实验表明, 胞外0m mol/ L Ca2 + 时胞内静息[Ca2 + ] i 为20 .2±8 .6nmol/L(n = 8) 。10μmol/L 5- HT 可诱导出胞内钙库释放引起的瞬态[Ca2 +]i 升高,其峰值达245 .7 ±71.6nmol/ L(n = 6) 。10 - 7 mol/L 硝普钠(SNP) 可抑制5- HT 诱导的[Ca2 +]i 升高,其峰值浓度降为75.1±35 .9nmol/L(n = 5) 。当细胞浴液含2.5m mol/L Ca2 + 时,静息[Ca2 +]i为112 .8 ±10 .3nmol/ L(n = 5) , 这时10μmol/ L 5 - HT 可诱导[Ca2 + ] i 的峰值为252 .3 ±80 .6nmol/L(n = 4) ,以及其后平台浓度为143 .0 ±37 .6nmol/L(n = 4) ,略大于[Ca2 +]i 为112.8 ±10 .3nmol/L 的静息浓度,为外钙内流引起。10 - 7 mol/L SNP 也可抑制5- HT 诱导[Ca2 + ]i 平台相浓度。平台浓度由143 ±47  相似文献   

4.
丹皮酚对心肌细胞自律性和延迟后除极的影响   总被引:8,自引:0,他引:8  
目的与方法:采用常规玻璃微电极技术研究丹皮酚对离体心肌细胞自律性(AM)、延迟后除极(DAD) 及触发活动(TA)的影响。结果:1.8×10-4mol/L丹皮酚灌流组,肾上腺素(Adr)的阈浓度空白对照组为(1.28±0.57)μmol/L,药后为(1.56±0.53)μmol/L(n=9,P>0.05);用(1.8×10- 3) mol/L丹皮酚(Pae)灌流组,Adr 浓度由空白对照组的(1.22 ±0.62)μmol/L升高到(6.22±2.11)μmol/L(n=9,P<0.01)。1.8×10-3mol/L的Pae 能明显抑制哇巴因(Oua)诱发的DAD的幅值,当基本刺激周长为500,400,300 和200 ms 时,其DAD幅值从(5.5±2.0)mV,(7.3±2.1)mV,(8.0 ±2.4)mV和(9.2±1.9)mV减小到(3.0±1.1)mV、(3.6±1.7)mV,(4.3±2.0) mV和(5.9 ±1.6) mV,P<0.01。当基本刺激周长为200 ms时,TA 数目由5.5±1.0 降至0.7±0.3(P<0.01)。结论:丹皮酚能抑制心肌细胞AM、DAD及TA,具有抗心律失常作用  相似文献   

5.
甘肃鼢鼠种群性比的研究   总被引:11,自引:1,他引:10  
本文对甘肃鼢鼠种群的性比及性比的季节,年度和年龄组的变化进行了研究,并对种群性比与月平均气温,降水量等环境因子间的关系进行了分析,结果表明,甘肃鼢鼠种群的总性比(♀/♂)为1.57,雌性明显多于雄性(X^2=47.6,P〈0.01),并且,种群性比存在明显的季节和年龄变化,但性比的年度变化不明显,在4-8月份鼢鼠繁殖期,月降水量〈5mm,或月降水量〉40mm的月份,月降水量与其后一月鼢鼠种群性比之  相似文献   

6.
小麦族几种近缘植物细胞在长期离体培养中的染色体变异   总被引:7,自引:0,他引:7  
对小麦及其4种近缘属间禾草进行了长时间(0.5~5.7年,个别8.6年)的愈伤组织培养,在继代过程中染色体数目的变异在染色体倍性低的簇毛麦(Haynaldia villosa,2n=2x=14)及新麦草(Psathyrostachys juncea,2n=2x=14)倾向于数目的增大;染色体倍性高的小麦(Triticun aestivun,2n=6x=42)趋向于数目的减少;而倍性居中的羊草  相似文献   

7.
本文报道了一种改进的阴茎电刺激采精法,用脱脂棉和铝箔作为电极,以避免直接用金属电极可能对阴茎的损伤,并运用这一方法对猕猴(Macacamulatta)、藏酋猴(M.thibetana)和熊猴(M.assamensis)进行了电刺激采精及其精液特征研究。电刺激采精模式为连续刺激和间断刺激方式。在采精过程中没有发生阴茎损伤。对初次接受电刺激采精的动物以间断刺激模式效果较好。猕猴、藏酋猴和熊猴的射精体积分别为2.0±0.1、6.3±1.1和3.2±0.6ml;液化体积分别为0.7±0.6、2.1±0.4和1.7±0.3ml;精子浓度分别为12.6±1.2×10~8、45.6±5.6×10~8和11.5±0.9×10~8/ml。3种动物精液的液化率分别为:猕猴36.2±0.9%,藏酋猴34.0±1.4%;熊猴51.8±1.2%。3种动物的精子总数与射精体积和凝块体积没有相关性(r~2=0.079;0.016;0.094和r~2=0.064;0.020;0.072)。上述结果表明:1)改进的阴茎电刺激采精法适用于猕猴,特别是阴茎表面较为粗糙的藏酋猴和熊猴;2)藏酋猴的射精体积和精子总数是迄今已报道的非人灵长类中最大的,可能  相似文献   

8.
獐牙菜属5种植物的核型研究   总被引:4,自引:0,他引:4  
首次报道了中国5种獐芽菜属植物的染色体数目和核型。它们染色体中期核和相对长度组分分别是:四数獐牙菜为2n=14=4m+8sm+2st=2L+6M2+4M1+2S;华北獐牙菜2n=28=12m+14sm+2st=6L+8M1++6S;二叶獐牙菜为2n=28=14m+4sm+10st=2L+14M2+101+sS;抱茎獐 菜为2n=6m+12sm+2st=8M2+12M;浙江獐牙菜为2n=20=8m+  相似文献   

9.
荒漠沙蜥繁殖生态研究   总被引:9,自引:0,他引:9  
刘逎发  陈强  解雪梅 《生态学报》1996,16(3):276-282
荒漠沙蜥(Phrynocephalusprzewalskii)1年繁殖1次,有明显的季节性周期。4月初出蛰时雄性精巢已相当发育,5月其重量和体积最大,6月变小,进入精子发生的晚期,7月降到最小,8月开始回升,10月中旬入蛰时已接近春季出蛰时水平。1年内仅7月精巢中无精子。雌性出蛰后卵细胞开始发育,4月下旬进入成熟期,6月达高峰,7月下降,8月进入休止期。每雌年产卵1~3枚或1~4枚,平均1.83(n=48,1987)和2.17(n=48,1993)。特定体长组的生殖率是影响种群年平均生殖率的主要因素。生殖周期与光周期相符,光周期是影响荒漠沙蜥生殖周期的主要气候因子。  相似文献   

10.
深圳湾大弹涂鱼种群结构与生殖特征   总被引:8,自引:0,他引:8  
蔡泽平 《生态学报》1996,16(1):77-82
本文探讨了深圳湾大弹涂鱼种群结构和生殖特征。结果表明:该种群以1、2龄鱼组成为主,3龄鱼极少,表明种群结构简单,体长与体重的相关曲线方程为W=4.1618×10-5L2.7451(r=0.9576)。雌雄性比为3:2。一龄鱼开始性成熟。雌鱼性成熟最小生物学体长为62mm,雄鱼为59mm。个体绝对生殖力波动于1956—14053粒,平均7293粒;个体相对生殖力F/L:29.5—100.5粒/mm,平均79粒/mm;F/W:511.0—804.9粒/g,平均752粒/g。4—6月为繁殖盛期,7—8月为繁殖末期。雌性周年月平均成熟系数(GSI)变动范围为0.27%—4.36%。大弹涂鱼在一个生殖季节中只能产卵一次,属于一次性排卵类型。  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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