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1.
棕背鼠最适生境及其主导因子分析THEOPTIMALBIOTOPEOFLARGE-TOOTHEDRAD-BACKEDVOLEANDTHEANALYSESOFITSMAINFACTORSKeywordsLarge-toothedrad-dackedvol...  相似文献   

2.
池塘养殖环境中底质-水界面营养盐扩散通量的现场测定   总被引:3,自引:0,他引:3  
孙耀 《生态学报》1996,16(6):664-669
池塘养殖环境中底质-水界面营养盐扩散通量的现场测定FIELDDETERMINATIONOFDIFFUSIONFLUXOFNUTRIENTSFROMSEDIMENT-WATERINTERFACEOFCULTUREPOND¥SunYao(YellowSe...  相似文献   

3.
披针叶胡颓子果实营养成分的测定毛学文(天水师范高等专科学校,天水741000)DETERMINATIONOFNUTRIENTCONSTITUENTSINSEEDSOFELAEAGNUSLANCEOLATAMaoXue-wen(TianShuiTeac...  相似文献   

4.
Ruan HZ  Fan XT 《生理学报》2000,52(2):119-122
用高原低氧模型及原位杂交、NADPH-d组织化学法,探讨氯氨酮和L-NAME对急性高原低氧大鼠下丘脑一氧化氮合酶(NOS)和生长抑素mRNA(SS mRNA)表达的影响。结果表明,急性高原低氧引起下丘脑NOS和SS mRNA过度表达,如先用NMDA受体拮抗剂氯氨酮和NOS抑制剂L-NAME预处理,NOS和SS mRNA的表达均明显被抑制。结果提示,NMDA受体参与了急生高原低氧引起的下丘脑NOS和  相似文献   

5.
油蒿和籽蒿种子化学组成的研究   总被引:1,自引:0,他引:1  
油蒿和籽蒿种子化学组成的研究鲁作民(中国科学院兰州沙漠研究所,兰州730000)STUDIESONCHEMICALCOMPOSITIONSINSEEDSOFARTEMISIAORDOSICAANDA.SPHAEROCEPHALA¥LuZuo-min(...  相似文献   

6.
mRNA很可能携带三维遗传信息(英文)   总被引:1,自引:0,他引:1  
mRNA很可能携带三维遗传信息MESSENGERRNAPROBABLYCARRIESTHETHREE-DIMENSIONALGENETICINFORMATIONTheformingmechanismofthethree-dimensionalstru...  相似文献   

7.
一种简便快速的蛋白质免疫印渍法介绍   总被引:10,自引:0,他引:10  
一种简便快速的蛋白质免疫印渍法介绍骆爱玲,王继伟,李佳格(中国科学院植物研究所,北京100044)ASIMPLEMETHODFORPROTEINBLOTTINGANDLMMUNOASSAYLuoAi-ling;WangJi-wei;Lijia-ge(...  相似文献   

8.
朝鲜蛾眉蕨配子体形态发育的研究   总被引:3,自引:0,他引:3  
朝鲜蛾眉蕨配子体形态发育的研究刘保东,王志宏(哈尔滨师范大学生物系,哈尔滨150080)OBSERVATIONONTHEFORMALDEVELOPMENTOFGAMETOPHYTEOFLUNATHYRIUMCOREANUM¥LiuBao-dong;W...  相似文献   

9.
中国伞滑刃线虫属─新纪录(真滑刃目:寄生滑刃科)   总被引:1,自引:0,他引:1  
中国伞滑刃线虫属─新纪录(真滑刃目:寄生滑刃科)THENEWRECORDOFBURSAPHELENCHUSFROMCHINA(APHELENCHIDA:PARASITAPHELENCHIDAE)¥YINGan-liu;FANGYu-sheng(Dep...  相似文献   

10.
沙竹中内生固氮菌的分离及鉴定   总被引:3,自引:0,他引:3  
沙竹中内生固氮菌的分离及鉴定李久蒂孙捷匡柏健陈仲新(中国科学院植物研究所,北京100093)ISOLATIONANDCHARACTERIZATIONOFENDOPHYTICDIAZOTROPHSINPSAMMOCHLOAMONGOLICALiJiu-...  相似文献   

11.
目的:通过观察肾上腺髓质素(ADM)mRNA在豚鼠哮喘模型肺内的表达及对哮喘豚鼠离体气管条张力的影响,研究ADM在支气管哮喘(简称哮喘)发病机制中的作用。方法:用原位杂交方法检测ADM mRNA在豚鼠哮喘模型肺内的表达,用组胺诱导豚鼠离体气管条收缩后,观察不同浓度的ADM对其收缩作用影响。结果:原位杂交结果显示正常及哮喘豚鼠肺内均有ADM mRNA的表达,但哮喘组较正常组明显增多(P<0.05),ADM可抑制组胺诱导的哮喘豚鼠离体气管条的收缩,并呈量效关系,当浓度达10^-8mol/L时抑经达到最大,而且即使加大ADM的浓度,抑制率未继续明显增加,并对致敏气管螺旋条的舒张作用明显大于正常气管螺旋条。结论:哮喘时,肺内ADM mRNA的表达明显增多,ADM可抑制组胺诱导的豚鼠离体气管条的收缩,浓度为10^-8mol/L时抑制率达到最大。提示ADM在哮喘发病过程中起重要作用。  相似文献   

12.
镁离子对阿霉素线粒体毒性的防护作用   总被引:10,自引:0,他引:10  
利用ESR技术研究了阿霉素与心肌线粒体的相互作用及Mg^2+的防护作用。结果表明:在线粒体及亚线粒体体系,Mg^2+可有效地抑制阿霉素半醌自由基产生,在一定浓度范围内抑制效果依赖于Mg^2+的浓度。另外,Mg^2+显著抑制阿霉素诱导产生的线粒体脂质过氧化。在亚线粒体体系,我们观察到阿霉素半醌自由基的固定化信号,并发现Mg^2+能明显延缓固定化信号出现。  相似文献   

13.
肾上腺髓质素对豚鼠心室肌细胞L-型钙通道的调制   总被引:1,自引:0,他引:1  
Du YM  Tang M  Liu CJ  Luo HY  Hu XW 《生理学报》2002,54(6):479-484
应用全细胞膜片钳技术研究了肾上腺髓质素 (ADM )对豚鼠心室肌细胞L 型钙电流 (ICa ,L)的影响及其信号传导机制。结果发现 :ADM ( 1~ 10 0nmol/L)浓度依赖性抑制ICa,L(P <0 0 5 ) ,并可被ADM特异受体阻断剂ADM2 2 52 ( 10 0nmol/L)完全阻断。用蛋白激酶A特异拮抗剂H 89( 10 μmol/L)预处理 ,对ADM抑制ICa ,L的作用无影响。但用蛋白激酶C (PKC)特异性拮抗剂PKC19 36 预处理 ,可完全阻断ADM的抑制效应 ;而PKC特异性激动剂PMA则可以模仿ADM的抑制效应 (P <0 0 5 )。上述结果提示 :ADM作用于特异性ADM受体可浓度依赖性地抑制豚鼠心室肌细胞ICa ,L,而此作用可能是PKC介导的。  相似文献   

14.
Qi YF  Xue L  Chai SB  Shi YR  Pang YZ  Tang CS 《生理学报》2001,53(5):396-400
新近研究发现,肾上腺髓质素(adrenomedullin,ADM)和降钙素基因相关肽(calcitonin gene-related peptide,CGRP)均能与降钙素受体样受体(calcitoni receptor-like receptor,CRLR)结合,其配体特异性由受体活性修饰蛋白(receptor activity-modifying protein RAMP)调控,本工作在离体培养的大鼠胸主动脉血管平滑肌细胞(vsacular smooth muscle cells,VSMCs)上观察ADM和CGRP受体脱敏现象,以探讨CRLR/RAMP假说在心血管组织方面的意义,用无血清培养基(serum-free medium,SFM)和含有10^-8mol/L ADM,CGRP和肾上腺髓素质前体原N-末端20肽(proadrenomedullin N-terminal 20 peptide PAMP)的SFM培养,再用10^-8mol/L ADM或 CGRP和磷酸二酯酶的抑制剂异丙基次黄苷(isobutyryl methyxanthine,IBMX)与VSMCs进行第二次孵育,然后收集细胞,测定VSMCs cAMP含量。10^-8mol/LADM,CGRP和PAMP单独与VSMCs孵育,VSMCs cAMP含量分别较SFM组高191%(P<0.01),385%(P<0.01)和67%(P<0.05),预先用10^-8mol/L ADM ak CGRP与VSMCs孵育可降低随后的CGRP刺激VSMCs产生cAMP,分别较单次CGRP育少44%(P<0.05)和48%(P<0.01),预先用100nmol/L蛋白激酶A(PKA)抑制剂H-89处理VSMCs,可完全阻断ADM和CGRP预处理诱导的第二次CGRP刺激的VSMCs cAMP含量减少,表明VSMCs对CGRP的脱敏过程是通过PKA途径实现的,预先用ADM,CGRP处理VSMCs后,用ADM第二次孵育,细胞内cAMP含量与单次ADM孵育无明显改变,PKA抑制H-89与VSMCs孵育,无论对欠ADM刺激或对ADM和CGRP处理的第二次刺激的cAMP生成均无影响,用PAMP处理VSMCs后,ADM和CGRP的第二次刺激的VSMCs cAMP水平无明显改变(P>0.05)。结果提示,在离体培养的大鼠VSMCs,ADM epc wsg i euk txgtdmj CGRP受体对预先用ADM和CGRP处理后的激动剂的第二次刺激都脱敏,表明ADM和CGRP的脱敏现象不一致。  相似文献   

15.
Possible mechanisms for nicotine-induced relaxation were investigated in the isolated sheep's sphincter of Oddi. Sheep's sphincter of Oddi rings were mounted in tissue bath with modified Krebs-Henseleit solution and aerated with 95% oxygen and 5% carbon dioxide. Tension was measured with isometric force transducers, and muscle relaxation was expressed as percent decrease of precontraction induced by carbachol. Nicotine (1 x 10(-5) to 3 x 10(-3) mol/L) produced concentration-dependent relaxation on sphincter of Oddi precontracted by carbachol (10(-6) mol/L). Nicotine-induced relaxation was 72.8 +/- 4.2% of precontraction with carbachol (10(-6) mol/L) (mean pD2 value, 3.76 +/- 0.05 mol/L). Nicotine-induced relaxation was not affected by N(w)-nitro L-arginine methyl ester (L-NAME) (3 x 10(-5) mol/L), methylene blue (10(-5) mol/L), indomethacin (10(-5) mol/L), hexamethonium (10(-5) mol/L), glibenclamide (10(-5) mol/L), 4-aminopyridine (10(-3) mol/L), tetraethylammonium (3 x 10(-4) mol/L), clotrimazole (10(-6) mol/L), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) (10(-6) mol/L), and anthracene-9-carboxylate (9-AC) (10(-6) mol/L), but potentiated by bupivacain (10(-5) mol/L). A calcium-antagonizing effect of nicotine was not observed. The results suggest that nicotine-induced relaxation of the sheep's sphincter of Oddi is not mediated by the release of prostaglandins, nitric oxide (NO), or a related substance; by the activation of potassium channels or chloride channels; or by the stimulation of nicotinic cholinoceptors. Potentiation of the nicotine-induced relaxation by bupivacain indicates that blockade of sodium channels may play a role in this relaxation.  相似文献   

16.
17.
Transmural nerve stimulation following sympathetic (guanethidine 10(-4) mol/L, phenoxybenzamine 2 X 10(-5) mol/L, propanolol 2 X 10(-6) mol/L) and muscarinic blockade (atropine 5 X 10(-5) mol/L) produces a relaxatory response in canine saphenous veins contracted with prostaglandin F2 alpha. This relaxatory response was shown previously to be resistant to tetrodotoxin. Transmural nerve stimulation (10 V, 1.0 ms) was applied as intermittent trains of stimuli of 30 s duration at frequencies of 1-32 Hz. The veins showed a frequency dependent relaxation (maximum 2.65 +/- 0.20 g). The stimulations were repeated in the presence of lignocaine (10(-3) mol/L), apamin (10(-8) mol/L), ascorbic acid (10(-4) mol/L), or catalase (50 micrograms/mL). The relaxatory response was unaffected by apamin, scorpion toxin, superoxide dismutase, ascorbic acid, and catalase (p greater than 0.05). However, lignocaine (10(-3) mol/L) reduced significantly the relaxatory response to transmural nerve stimulation in this preparation (p less than 0.05). In a separate group of veins, lignocaine (10(-3) mol/L)l abolished the contractile response to transmural nerve stimulation with little effect upon the contractile response to exogenous noradrenaline and the relaxatory responses to isoprenaline and sodium nitrite. These findings support the proposition that the nonadrenergic, noncholinergic tetrodotoxin-resistant relaxatory response observed with transmural nerve stimulation in the canine saphenous vein is mediated by a neural mechanism.  相似文献   

18.
Yang D  Tan Z  Pan JY  Wang TH 《生理学报》2002,54(1):17-22
实验利用大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMC)作为模型,观察17-β雌二醇(E2)对VSMC增殖和原癌基因c-fos表达的影响,并探讨VSMC源性一氧化氮(NO)在基中的作用,检测指标包括NO释放的测定,细胞计数、^3H-Tdr掺入,噻唑蓝(MTT)测定和c-fosmRNA表达,结果显示,E2(10^-12-10^-8mol/L)呈浓度依赖性地促进VSMC中NO的释放;10^-8mol/LE2能明显抑制10%小牛血清(FCS)和10^-7mol/L内皮素-1(ET-1)诱导的细胞增殖和DNA合成,E2的抑制作用均可被雌激素受体(ER)拮抗剂tamoxifen(10^-7mol/L)和一氧化氮合酶抑制剂L-NAME(10^-6mol/L)明显减轻;E2(10^-8mol/L)可明显抑制10^-7mol/LET-1诱导的VSMCc-fos表达,这种抑制作用可被L-NAME(10^-6mol/L)明显减轻,这些结果提示E2能抑制VSMC增殖和原癌基因c-fos表达,这种促进VSMC的NO释放密切相关,而且该作用至少部分通过ER介导。  相似文献   

19.
Adrenomedullin (ADM) is upregulated in cardiac tissue under various pathophysiological conditions, particularly in septic shock. The intracellular mechanisms involved in the effect of ADM on adult rat ventricular myocytes are still to be elucidated. Ventricular myocytes were isolated from adult rats 4 h after an intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg). Membrane potential and L-type calcium current (I(Ca,L)) were determined using whole cell patch-clamp methods. APD in LPS group was significantly shorter than control values (time to 50% repolarization: LPS, 169 +/- 2 ms; control, 257 +/- 2 ms, P < 0.05; time to 90% repolarization: LPS, 220 +/- 2 ms; control, 305 +/- 2 ms, P < 0.05). I(Ca,L) density was significantly reduced in myocytes from the LPS group (-3.2 +/- 0.8 pA/pF) compared with that of control myocytes (-6.7 +/- 0.3 pA/pF, P < 0.05). The ADM antagonist ADM-(22-52) reversed the shortened APD and abolished the reduction of I(Ca,L) in shock myocytes. In myocytes from control rats, incubating with ADM for 1 h induced a marked decrease in peak I(Ca,L) density. This effect was reversed by ADM-(22-52). The G(i) protein inhibitor, pertussis toxin (PTX), the protein kinase A (PKA) inhibitor, KT-5720, and the specific cyclooxygenase 2 (COX-2) inhibitor, nimesulide, reversed the LPS-induced reduction in peak I(Ca,L). The results suggest a COX-2-involved PKA-dependent switch from G(s) coupled to PTX-sensitive G(i) coupling by ADM in adult rat ventricular myocytes. The present study delineates the intracellular pathways involved in ADM-mediated effects on I(Ca,L) in adult rat ventricular myocytes and also suggests a role of ADM in sepsis.  相似文献   

20.
非洲爪蟾卵母细胞GABAB和GABAc受体介导的电流反应   总被引:4,自引:0,他引:4  
Yang Q  Li ZW  Wei JB 《生理学报》2001,53(4):311-315
实验应用双电极电压箝技术,在具有滤泡膜的非洲爪蟾(Xenopuslaevis)卵母细胞上记录到γ-氨基丁酸(γ-aminobutyricacid,GABA)-激活电流。此GABA-激活电流的特点及有关GABA受体类型的研究和分析如下(1)在35.5%(55/155)的受检细胞外加GABA可引起一慢的浓度依赖性的外向电流。(2)GABAA受体的选择性拮抗剂bicuculline(10  相似文献   

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