苯并[a]芘暴露对三疣梭子蟹鳃、肝胰腺组织毒理学指标的影响1

本文研究了三疣梭子蟹(Portunus trituberculatus)在对苯并[a]芘(Ba P)富集(15 d)、释放(15 d)过程中其鳃和肝胰腺组织的4种毒理学指标的响应。4种毒理学指标分别为7-乙氧基异吩噁唑酮-脱乙基酶(EROD)、谷胱甘肽硫转移酶(GST)、超氧化物歧化酶(SOD)和脂质过氧化(LPO)。设置了0.05μg/L和0.45μg/L两个实验组以及海水和丙酮对照组。结果显示,在富集阶段,与海水对照组相比,第1天时0.05μg/L和0.45μg/L实验组鳃、肝胰腺组织的各毒理指标均显著受到诱导(P0.05),诱导程度随Ba P暴露浓度的增加而增大。而后鳃、肝胰腺组织的EROD、GST活性以及鳃组织的SOD活性达到峰值后下降,肝胰腺组织的SOD活性以及鳃、肝胰腺组织的丙二醛(MDA)含量则持续增加。鳃组织的EROD、GST、SOD活性到达峰值时间早于肝胰腺组织,其活性以及MDA含量也低于肝胰腺组织。在释放阶段,0.45μg/L实验组鳃组织的SOD活性,0.05μg/L和0.45μg/L两个实验组肝胰腺组织的SOD活性均依然显著高于同期海水对照组水平(P0.05),其余各浓度实验组鳃、肝胰腺组织均能恢复到同期海水对照组水平(P0.05)。实验结果表明,三疣梭子蟹的鳃组织对于Ba P暴露响应时间比肝胰腺组织更早,但均具有一定的恢复能力。     

低盐胁迫对三疣梭子蟹组织中抗氧化酶和 AT P 酶活力的影响

设定半致死低盐试验组(盐度 7)和正常对照组(盐度 28)对三疣梭子蟹进行 48h 的胁迫, 检测半致死盐度胁迫下不同时间点三疣梭子蟹组织中抗氧化酶和 ATP 酶活力的变化。结果显示, 随着低盐处理时间的延长, 三疣梭子蟹肝胰腺、鳃、肌肉中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力均呈下降趋势, 极显著低于对照组(P<0.01), 各组织中 SOD、 CAT 活力大小顺序为肌肉 >肝胰腺>鳃; 肝胰腺、鳃中谷胱甘肽过氧化物酶(GPX)、谷胱甘肽转硫酶(GST)、谷胱甘肽还原酶(GR)、Na+/K+-ATPase 酶和 Ca2+/Mg2+-ATPase 酶活力也都被抑制, 活力极显著下降(P<0.01); 而对照组在试验期间各组织酶活均较 平稳, 变化不大。试验结论表明 , 当盐度下降剧烈, 超出机体耐受范围时, 三疣梭子蟹生理机能被抑制, 酶活力反而下降。     

邻苯二甲酸二丁酯(DBP)胁迫对三疣梭子蟹亚急性毒性

研究不同浓度邻苯二甲酸二丁酯(DBP)对三疣梭子蟹相关酶活的影响及组织损伤。设置了三个处理浓度(0.03 mg/L、0.2 mg/L和0.4 mg/L)分别在第0、5、10、15、20 d进行取样。结果表明,随着DBP浓度的增大,三疣梭子蟹死亡率升高。在0.03 mg/L浓度组胁迫下,血清超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和碱性磷酸酶(AKP)活性呈现升高-下降交替波动,过氧化物酶(POD)活性在第10 d低于对照组(P<0.05),其余时间与对照组持平,酸性磷酸酶(ACP)活性在第5 d较对照组显著升高(P<0.05),此后一直保持对照组水平;在0.2 mg/L浓度组胁迫下,血清SOD活性呈现先升高后下降的趋势,POD活性变化不明显,CAT活性先下降后升高,此后恢复到对照组水平,ACP活性在第15 d出现最高值,其余时间与对照组持平,AKP活性呈现先升高后恢复的波动趋势;0.4 mg/L浓度组SOD、CAT和AKP活性呈现先升高后下降的趋势,POD活性和ACP活性在第20 d较对照组低(P<0.05),其余时间与对照组持平。组织切片观察可见,DBP胁迫损伤了三疣梭子蟹肝胰腺和鳃组织,DBP浓度越大,胁迫时间越长,损伤越明显。     

镉对长江华溪蟹酶活性及脂质过氧化的影响

本实验于2005年3-7月,采用急性毒性实验方法,研究了镉(Cd)对长江华溪蟹(Sinopotamon yangtsekiense)酶活性及脂质过氧化产物的影响.Cd处理设5个浓度组,分别为7.25mg/L、14.5mg/L、29mg/L、58mg/L和116mg/L,实验同时设对照组.分别在24h、48h、72h和96h取肝胰腺和鳃进行超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性的测定和脂质过氧化产物丙二醛(MDA)含量的测定.结果显示,在实验剂量范围内,随着镉浓度的增加和处理时间的延长,SOD和GSH-Px的活性均呈现先增高后降低的趋势,并存在组织差异性;而组织中MDA的含量随镉浓度的增加和处理时间的延长而升高.当处理时间为48h、Cd浓度为14.5mg/L时,肝胰腺和鳃中SOD活性均达最大值,较对照组差异极显著;当处理时间为48h、Cd浓度为7.25mg/L时,肝胰腺中GSH-Px活性达最大值,较对照组差异极显著;当处理时间为24h、Cd浓度为14.5mg/L时,鳃中GSH-Px活性达最大值,较对照组差异极显著.伴随处理时间和Cd浓度的增加,SOD和GSH-Px的活性开始逐渐下降.肝胰腺和鳃中GSH-Px/SOD的比值在对照组中处于平衡状态,但是在处理组中失去了平衡,有降低的趋势.结论:SOD与GSH-Px的活性和MDA含量的变化可以灵敏地反映Cd的胁迫程度及毒性大小.     

苯并(a)芘与壬基酚对河川沙塘鳢的联合毒性研究

为探究环境内分泌干扰物联合毒性对鱼类的影响,选取苯并芘(benzo[a]pyrene,BaP)及千幕酚(4-nonlyphenol,NP)对河川沙塘鳢Odontobutis potamophila进行单独和联合毒性研究.研究了NP和BaP对河川沙塘鳢血清雌二醇(E2)、卵黄蛋白原(Vtg)、血清谷草转氨酶(GOT)以及肝脏7-乙氧基-3-异吩咏唑酮-脱乙基酶(7-ethoxyresoufin-O-deethylase,EROD)和超氧化物岐化酶(SOD)的影响.结果 表明,BaP单一暴露时,随着BaP剂量浓度的升高雌鱼血清E2含量下降,肝脏EROD活性升高;25 mg/kg BaP试验组雌鱼肝脏EROD活性显著高十对照组;肝脏SOD和血清GOT活性与对照无筹异;NP和BaP联合暴露中,200 mg/kg NP+10 mg/kg BaP、200 mg/kg NP+2 mg/kg BaP试验组雄性个体血清Vtg平均含量比200 mg/kg NP组低50%左右,而血清E2含最显著高于对照组,肝脏EROD酶活性、血清GOT活性变化与BaP剂量浓度呈正相关,而肝脏SOD酶活性则与BaP剂量浓度呈负相关;200 mg/kg NP+25 mg/kg BaP试验组肝脏SOD活性显著低于对照组,而血清GOT活性则显著高于对照组.显示NP和BaP联合作用时BaP可拮抗NP对雄鱼Vtg的诱导效应;200 mg/kg NP+2 mg/kg BaP可导致河川沙塘鳢肝脏肝细胞损伤.     

三疣梭子蟹蜕壳周期肝胰腺、外壳和鳃中钙含量的变化

研究测定了三疣梭子蟹蜕壳周期肝胰腺、鳃和外壳中的钙含量。结果显示,在不同时间,鳃中钙含量变化较小,各时间点差异不显著;蜕壳前期至蜕壳刚完成阶段三疣梭子蟹(软壳蟹)肝胰腺中钙含量最高,蜕壳后第4 d肝胰腺中钙含量最低。三疣梭子蟹外壳中钙含量随着外壳的硬化(钙化)逐渐增加,完全硬化后外壳中钙含量达到最高。研究表明,蜕壳后三疣梭子蟹肝胰腺中钙含量的降低与外壳的钙化之间具有关联性,肝胰腺在三疣梭子蟹蜕壳后钙的储存中起着重要作用,而鳃在钙离子储存中所起的作用可能小于钙转移的作用。     

三疣梭子蟹不同组织同工酶的分析

采用垂直板状聚丙烯酰胺凝胶电泳技术 ,分析了三疣梭子蟹 (Portunustriuberbuculatus)雌性成体心脏、鳃、肌肉、眼睛、肝胰腺和卵巢 6种组织中的 1 0种同工酶 (ADH、MDH、ME、LDH、α AMY、GDH、SOD、SDH、EST和GOT)的分化表达模式 ,并对各种酶的同工酶位点表达及酶谱表型进行了分析。结果显示 ,三疣梭子蟹的同工酶系统具有明显的组织特异性。     

恩诺沙星在三疣梭子蟹主要组织中的代谢动力学

应用反相高效液相色谱法（RP-HPLC）研究了三疣梭子蟹（portunus trituberculatus）经口灌10 mg/kg恩诺沙星后体内的药代动力学规律。结果表明口灌给药后,三疣梭子蟹肝胰腺、肌肉和血淋巴组织中的恩诺沙星达峰速度快,肝胰腺和血淋巴在给药24h都有双峰现象出现。恩诺沙星在肝胰腺、肌肉、血淋巴中的Cmax分别为11.235μg/g、0.850μg/g和0.858μg/g,Vd/F为7.954 L/kg、10.367 L/kg和0.345 L/kg。t1/2β分别为283.361 h、47.869 h和17.681 h,AUC分别为245.618μg/g.h、24.753μg/g.h和20.111μg/g.h。给药后5 min在肝胰腺中即可检测到恩诺沙星的代谢产物环丙沙星,而肌肉和血淋巴在给药后2 h才能检测到,其含量均处于较低水平。用3P97软件对各组织中的药时数据进行房室模型拟合,结果显示：三疣梭子蟹口灌给药后,恩诺沙星在血淋巴、肌肉和肝胰腺中的代谢过程均符合一级吸收二室开放模型,而环丙沙星不能用房室模型来描述。     

急性低氧/复氧胁迫对克氏原螯虾抗氧化-能量代谢的影响

为研究低氧/复氧胁迫对克氏原螯虾(Procambarus clarkii)抗氧化及能量代谢的影响,将克氏原螯虾暴露于(1.0±0.1) mg/L急性低氧胁迫和后续(6.8±0.2) mg/L复氧环境中,于低氧胁迫1h、6h及复氧1h、12h分别采集肝胰腺、鳃和血淋巴,研究低氧/复氧胁迫下克氏原螯虾抗氧化-能量代谢酶的活力变化,分析鳃和肝胰腺组织的超微结构改变。在低氧胁迫下,肝胰腺和血淋巴中SOD酶活力显著下降(P<0.05);复氧以后,肝胰腺、血淋巴及鳃组织中SOD酶活力均出现了显著上升(P<0.05)。SOD酶活力变化可能与复氧过程中超氧阴离子自由基的过量产生有关。在复氧12h后,血淋巴和鳃组织中MDA含量均出现了显著性增加(P<0.01),提示机体细胞在复氧胁迫下产生了脂质过氧化。在低氧胁迫下,肝胰腺、鳃和血淋巴中ACP、AKP酶活力显著上升(P<0.05);在复氧12h后,肝胰腺和鳃组织中ACP酶活力显著降低(P<0.01)。显示低氧/复氧胁迫影响了机体的非特异性免疫应答。在急性低氧胁迫下,肝胰腺、血淋巴与鳃组织中的LDH含量和总ATPase活力均显...     

镧对鲤鱼五种组织超氧化物歧化酶同工酶及酶活性的影响

将鲤鱼暴露于不同浓度的氯化镧溶液120 d,研究稀土元素镧对鲤鱼脑、肝胰脏、肾、鳃、肌肉5种组织超氧化物歧化酶(SOD)同工酶及酶活性的长期影响,结果表明:镧对SOD的影响表现出一定的组织差异性.在实验浓度范围内(0.01～5 mg/L),镧对肝胰脏、鳃、肌肉SOD均有明显抑制作用,且与对照组相比相差显著或极显著(P< 0.05或P< 0.01),而脑、肾SOD活性与对照组相比无显著性差异(P>0.05).同工酶电泳实验结果表明:镧能使鲤鱼肝胰脏、脑、肾、肌肉、鳃SOD酶带活性强弱发生明显变化,还能使肝胰脏SOD同工酶酶带缺失.     

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.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

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。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

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.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.