乙酰胆碱协同剂对蚕豆保卫细胞原生质体内钾电流的调节作用

用膜片钳全细胞记录方式研究了乙酰肝碱对蚕豆保卫原生质体内向钾电流的作用与机理。发现乙酰胆碱的协同剂－－烟碱和毒草碱分别促进内向钾电流３０％－４０％。ＥＧＴＡ处理能有效减弱毒草碱对内向钾电流的促进效应,但不影响烟碱对内向电流的促进效应。这些结果提示,乙酰胆碱促进气孔开放的作用可能是通过受体直接或间接调节内向钾电流实现的。     

乙酰胆碱及其拮抗剂对蚕豆保卫细胞内向钾电流的调节作用

用膜片钳全细胞记录方式记录蚕豆保卫细胞原生质体内向钾电流,结果发现,低浓度乙酰胆碱处理促进内向钾电流,高浓度乙酰胆碱处理则抑制内向钾电流.乙酰胆碱受体的拮抗剂d-管箭毒和阿托品分别抑制的内向钾电流约30%;同时使用d-管箭毒和阿托品则抑制60%～75%的内向钾电流,四乙铵离子处理不影响乙酰胆碱调节的内向钾电流.以上结果表明,乙酰胆碱及其受体可能是通过调节保卫细胞质膜上的内向钾通道参与对气孔运动的调节.     

迷走神经功能调节与心肌缺血保护

心血管系统的生理活动受自主神经系统(autonomic nervous system,ANS)调节.已有研究表明,自主神经功能紊乱,尤其是迷走神经功能低下,与心血管疾病(cardiovascular disease,CVD)的发生、发展及预后密切相关.本文结合国内外研究现状,就本研究室在迷走神经对心脏不同部位的调控及其对心肌的保护作用机制方面的研究成果进行阐述.通过收缩功能检测及标准玻璃微电极细胞内记录技术,发现迷走神经递质--乙酰胆碱对哺乳动物心室肌有直接作用,可抑制细胞收缩力及动作电位时程;通过组织化学染色及分子生物学方法进一步证明心室有毒蕈碱受体分布;通过膜片钳技术显示在部分动物心室肌上存在乙酰胆碱激活的内向整流钾通道(acetylcholine-activated potassium channel,KACh),并且其电流(IK·ACh)和心房肌一样具有衰减现象.前期研究证明心房肌IK·ACh的衰减与毒蕈碱受体、G蛋白或钾通道磷酸化有关;而心室肌的IK·ACh还有待于进一步研究.我们建立了相关动物模型,结合心率变异性分析等自主神经评价方法,探讨ANS在健康和疾病状态下的变化情况,证明了迷走神经对心脏调节的增龄性改变及代偿效应.通过提高迷走张力(乙酰胆碱缺血预/后适应、有氧运动、β受体阻断剂),研究改善自主神经平衡对缺血心肌的保护作用以及胆碱能抗炎通路防御缺血,再灌注诱导的炎症损伤机制.综合评价心脏自主神经调节,改善交感和迷走张力平衡,将为CVD防治的基础研究提供重要的理论依据.     

乙酰胆碱信号通路在肺癌中的作用

肺癌作为当今世界最为致命的疾病之一,严重地威胁着人类的生命健康。神经递质乙酰胆碱(acetylcholine,ACh)作为肺癌的自分泌和旁分泌生长因子,可与肺癌细胞上的烟碱型乙酰胆碱受体(nicotinic acetylcholine receptor,nAChRs)和毒蕈碱型乙酰胆碱受体(muscarinic acetylcholine receptors,mAChRs)结合,促进肺癌细胞的增殖、迁移和侵袭。近年来,全基因组数据研究表明,nAChRs与吸烟相关肺癌风险密切相关,因此其在肺癌发生发展中的作用机制的研究对肺癌药物的研发具有重要意义。本文对乙酰胆碱信号通路在肺癌进展中的作用机制进行综述,为其成为肺癌治疗新分子靶点和药物的开发提供依据。     

柯萨奇B3病毒对心肌细胞离子通道电流的影响

目的 :探讨柯萨奇B3病毒 (coxsackievirusB3,CVB3)对大鼠心肌细胞离子通道的影响 ,以了解病毒感染导致细胞电生理活动异常的机理。方法 :酶消化法获得单个心肌细胞后利用膜片钳全细胞电流记录技术观察CVB3对L型钙通道电流、钠通道电流、外向钾电流和内向整流性钾电流的影响。结果 :CVB3感染使L型钙通道电流、外向钾电流增加 ,内向整流性钾电流减小 ,对钠通道电流无明显影响。结论 :CVB3对L型钙通道电流、外向钾电流和内向整流性钾电流的影响可能是病毒感染后细胞损伤和产生异常电活动的原因。     

大鼠颈上神经节烟碱电流的整流及失敏

在培养的新生大鼠颈上神经节交感神经元标本上,用全细胞膜片钳技术研究了烟碱型乙酰胆碱受体（ｎＡＣｈＲ）通道的整流及失敏现象。烟碱激动剂引起的全细胞电流在膜电位为负值时随膜电位呈线性改变,而在膜电位达＋６０ｍＶ时仍不出现外向电流,表现出强烈的内向整流。ｎＡＣｈＲ通道电流存在失敏现象,即持续恒压喷射激动剂所引起的全细胞电流随时间呈指数衰减,不能保持在峰值水平,失敏随激剂浓度呈量效关系,膜电位的超极化也加     

烟碱型乙酰胆碱受体参与乙酰胆碱调控的气孔运动

动物细胞中 ,乙酰胆碱功能的发挥要求乙酰胆碱受体的参与 ,烟碱型受体的激活剂可以直接影响膜对离子的通透性 .在乙酰胆碱诱导的气孔开放过程中 ,可能同样涉及到烟碱型受体的作用 ,药理学的证据表明烟碱型乙酰胆碱受体参与乙酰胆碱调控的气孔运动 ,而且烟碱型乙酰胆碱受体介导的气孔开放与介质中的离子组成密切相关 ,只有在含K⁺的介质中烟碱才可以诱导气孔开放而在含Ca^{2 +}的介质中没有作用 ;同样 ,烟碱型乙酰胆碱受体的抑制剂只有在含K⁺的介质中才能抑制乙酰胆碱诱导的气孔开放 .进一步利用荧光定位技术证明烟碱型受体存在于蚕豆气孔保卫细胞中 ,而且主要分布在保卫细胞原生质体的表面 .免疫印迹实验初步证明在保卫细胞原生质体的微粒体中存在着能与动物烟碱型乙酰胆碱受体的α和β亚基发生免疫交叉反应的蛋白条带 .以上结果表明烟碱型乙酰胆碱受体存在于保卫细胞中 ,而且介导了乙酰胆碱诱导的气孔在含K+介质中的开放 .     

淋巴细胞上的非神经性乙酰胆碱系统

尽管乙酰胆碱作为神经递质存在于哺乳动物神经系统中的事实已广为人知,但近年来在淋巴细胞等非神经性组织和细胞中也发现了乙酰胆碱。淋巴细胞具备一个独立的非神经性乙酰胆碱系统,包括:乙酰胆碱、胆碱酯酶、胆碱乙酰转移酶、毒蕈碱乙酰胆碱受体和烟碱能乙酰胆碱受体等组分。免疫系统与淋巴细胞胆碱能系统之间可以相互作用。免疫刺激后的淋巴细胞可增强胆碱能系统的表达;激活后的乙酰胆碱受体参与淋巴细胞的免疫调节。淋巴细胞上胆碱能系统的这些发现将为相关疾病的研究和寻找有效的防治药物提供新的研究思路。     

淋巴细胞上的非神经性乙酰胆碱系统

尽管乙酰胆碱作为神经递质存在于哺乳动物神经系统中的事实已广为人知,但近年来在淋巴细胞等非神经性组织和细胞中也发现了乙酰胆碱。淋巴细胞具备一个独立的非神经性乙酰胆碱系统,包括:乙酰胆碱、胆碱酯酶、胆碱乙酰转移酶、毒蕈碱乙酰胆碱受体和烟碱能乙酰胆碱受体等组分。免疫系统与淋巴细胞胆碱能系统之间可以相互作用。免疫刺激后的淋巴细胞可增强胆碱能系统的表达;激活后的乙酰胆碱受体参与淋巴细胞的免疫调节。淋巴细胞上胆碱能系统的这些发现将为相关疾病的研究和寻找有效的防治药物提供新的研究思路。     

d-尼古丁对血管平滑肌细胞迁移的影响

为了在分子水平上揭示吸烟导致动脉粥样硬化的机制,探讨了烟草致病的主要成分d-尼古丁对豚鼠大脑基底动脉血管平滑肌细胞GbaSM-4迁移作用的影响。应用Boyden小室实验发现,d-尼古丁具有促进GbaSM-4细胞迁移的作用。免疫荧光染色显示,在d-尼古丁作用下有GbaSM-4细胞伪足内肌动蛋白表达和分布增加的现象。为了进一步阐明d-尼古丁促进平滑肌细胞迁移作用的分子机制,应用RT-PCR方法检测到在GbaSM-4细胞内有α7型烟碱乙酰胆碱受体的表达。应用烟碱乙酰胆碱受体的特异性抑制剂甲基牛扁碱和肌肉收缩的关键酶——肌球蛋白轻链激酶（myosin light chain kinase,MLCK）抑制剂ML-9作用GbaSM-4细胞后,发现d-尼古丁对GbaSM-4细胞的诱导迁移作用被明显的抑制。采用RNA干扰技术,成功地使GbaSM-4细胞内MLCK的表达水平下调,观察到d-尼古丁对GbaSM-4细胞的诱导迁移作用也被明显的抑制。上述研究结果表明,d-尼古丁以趋化因子的作用促进血管平滑肌细胞迁移,其分子机制可能与α7型烟碱乙酰胆碱受体和MLCK等因素有关,这一发现为揭示吸烟导致动脉粥样硬化提供了实验依据。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.