首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 175 毫秒
1.
30年代日本小林等对珍珠贝外套膜组织结构及珍珠囊形成组织学作过观察,指出了外套膜、外表皮(壳侧表皮)与珍珠囊表皮细胞形态上存在着明显差异及细胞分泌特点;后经许多珍珠学者不断拓展,逐步形成了目前已基本上定论的珍珠分泌组织学及分泌机制。作者观察到几种淡水河蚌外套膜组织及一些尚未被描述的分泌结构:这些物质与外表皮分泌物一致,能够解释贝类组织学及珍珠(贝壳)形成机制上的一些重要问题,且在某些见解上与上述文献报道有较多出入。因此,有必要对实验结果作分析报道,供今后进一步研究作参考。  相似文献   

2.
褶纹冠蚌光珠与骨珠珍珠囊差异的研究   总被引:7,自引:0,他引:7  
运用多种组织化学方法和电镜技术研究了褶纹冠蚌光珠和骨珠珍珠囊表皮细胞的形态结构、分泌物性质和功能等方面的差异。结果表明:骨珠珍珠囊表皮细胞合成和分泌珍珠前体物质的能力较光珠的强,故骨珠的形成速度比光珠快;光珠和骨珠珍珠囊表皮细胞合成和分泌的蛋白质的差异决定了光珠和骨珠的形成;光珠和骨珠珍珠囊表皮细胞的形态结构特征差异可作为检验和预测人工培育珍珠质量的细胞学标准。  相似文献   

3.
本文采用H.E染色法和酶组织化学方法,对背角无齿蚌珍珠囊形成过程的组织学和酶组织化学的变化情况进行了研究,证实了“初生珍珠囊”的形成和溶解及“次生珍珠囊”的形成,并推没“次生珍珠囊”表皮细胞是由育珠蚌结缔组织转化而来的;观察了育珠手术后九种酶在珍珠囊形成的各个阶段和在珍珠囊和育珠蚌不同部位的变化情况,说明了珍珠囊珙成过程是与复杂的能量代谢,物质代谢及物质转运等有关的生理生化过程。  相似文献   

4.
背角无齿蚌珍珠囊形成过程中钙代谢的初步研究   总被引:2,自引:0,他引:2  
本文采用同位素活体标记、人工育珠、普通石蜡切片和放射自显影的方法,对一种淡水育珠河蚌──背角无齿蚌珍珠囊形成过程中的钙代谢途径进行了研究,结果表明,由植入小片带入的钙在珍珠囊形成的过程中,主要代谢途径是:(1)随小片细胞脱落而进入游走细胞;(2)从小片进入初生珍珠囊,初生珍珠囊脱落后进入游走细胞;(3)从小片进入育珠蚌结缔组织,其中一部分再进入育珠蚌表皮,随粘液和壳质分泌;另一部分则进入次生珍珠囊表皮,分泌成为珍珠质的组成部分。实验结果说明了小片中的钙要参与育珠蚌组织的钙代谢,小片的质量对珍珠形成有重要的作用。  相似文献   

5.
以圆前角无齿蚌为材料,采用外套膜小片的异体移植与加入血细胞的体外培养,研究了血细胞在体风,唯物 修复及珍珠囊构建中的功能。结果表明人工育珠手术后的损伤修复中,血细胞有形成无颗粒细胞层修复伤口、6诱导表皮细胞迁移和再生并形成珍珠囊的功能,而在体外的组织培养中加入血细胞比不加入血细胞的对照组,能更快地诱导上皮细胞迁移和再生,在整个伤面形成2覆盖层,即形成类似珍珠囊结构。本文首次在国内、外报道了用细胞培  相似文献   

6.
三角帆蚌外套膜及珍珠囊的组织学初步观察   总被引:13,自引:0,他引:13  
近些年来,人们对海水马氏珠母贝(Pinctada martensii)和淡水池蝶蚌(Hyriopsis schlegelii)等双壳类外套膜及珍珠囊进行了组织学、组织化学和体外培养等的研究,然而结合河蚌人工育珠方面的报道却不多。事实上,欲提高淡水珍珠质量虽取决于多种因素,但其中与取供体蚌中的外套膜外表皮制作植片用的小片部位,以及珍珠囊的形态结构有着非常密切的关系。因此,本文旨在能对提高河蚌人工育珠的质量提供一些参考。  相似文献   

7.
不同pH值对三角帆蚌珍珠质分泌的影响   总被引:14,自引:0,他引:14  
邱安东  石安静 《动物学报》1999,45(4):361-370
运用多种组织化学方法和透射电镜技术,研究了5种pH水环境(pH5、6、7、8、9)对三角帆砷外套膜珍珠质分泌的影响机制,结果表明,在中性水环境中,贝体能积极地从外界水环境中吸收钙,并能旺盛地合成和分泌贝壳珍珠层及珍珠有机基质前体物质,持续的酸性水环境导致贝体的钙严重丢失,并引起珍珠质分泌细胞对有机基质前体物质的合成和分泌能力减弱,持续的碱性水环境虽能导致贝体对钙的积累,但珍珠质分泌细胞合成和分泌珍  相似文献   

8.
本文研究河蚌外套膜组织培养细胞分泌珍珠质的药理作用。组织培养后的培养液,能缩短小白鼠出血时间。用组织培养后的培养液及组织块水解液,对大鼠离体子宫及蟾蜍离体心脏收缩有增强作用,对兔离体小肠有抑制作用。这些药理作用与培养液中牛磺酸含量变化一致。实验结果表明,河蚌分泌珍珠质的细胞,在离体人工培养条件下,能旺盛地分泌珍珠质,分泌的珍珠质具有天然珍珠相同的一些药理作用。  相似文献   

9.
褶纹冠蚌珍珠囊发育的研究   总被引:10,自引:1,他引:9  
以褶纹冠蚌(Cristaria plicata Leach)为实验对象,应用光学显微技术和扫描电子显微技术研究珍珠囊的发育,结果表明在水温16℃左右时约需30d形成具有单层上皮细胞的珍珠囊,6个月后稳定分泌珍珠质。构成珍珠囊的上皮细胞从高柱状逐渐变成扁平状或立方形,细胞的碳酸酐酶污性也日益增强。大部分移植细胞小片的结缔组织与母蚌的结缔组织共同成层排列在珍珠囊腔外围。游走细胞在珍珠囊的早期发育阶段十分活跃。本文还阐明了珍珠囊液是存在于上皮细胞与珍珠表面之间的一薄层流体状物质。碳酸钙结晶的核化(nucleation)和初期生长都发生在珍珠囊液中。  相似文献   

10.
珍珠颜色和贝壳珍珠层颜色研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
颜色及其色度均一性是衡量珍珠价值的重要指标之一。珍珠颜色及贝壳珍珠层颜色的研究涉及多个学科领域,研究表明,珍珠的颜色与制片蚌外套膜对应的珍珠层颜色相一致,而蚌的珍珠层颜色主要由遗传因素决定。现有的研究资料对珍珠层颜色形成的机理虽然还不能给出一个系统、合理的诠释,但金属元素、卟啉、类胡萝卜素和物理结构等因素可能和珍珠层颜色形成密切相关,珍珠层中含有少量以蛋白质为主的有机基质,这些蛋白调控珍珠层的结构和颜色的形成,可能是解释珍珠层颜色形成机理的关键。本文对珍珠颜色和贝壳珍珠层颜色研究进展进行系统综述,探讨珍珠颜色的影响因素及相互关联,旨在为进一步研究珍珠和贝壳珍珠层颜色提供借鉴与思路。  相似文献   

11.
Addition of copper sulfate (0.1 to 0.4 mg l(-1)) to tryptic soy broth (TSB) had no effect on growth rate of the bacterial pathogen Lactococcus garvieae. Giant freshwater prawns Macrobrachium rosenbergii were injected with L. garvieae (4 x 10(6) colony-forming units [cfu] prawn(-1)) grown in TSB or TSB containing copper sulfate at 0.1, 0.2, 0.3 or 0.4 mg l(-1). After 48 h, the cumulative mortality was significantly (p < 0.05) higher for prawns exposed to L. garvieae grown in 0.4 mg l(-1) copper sulfate than at the lower concentrations examined. In other experiments, prawns were injected with TSB-grown L. garvieae (4 x 10(6) and 2 x 10(5) cfu prawn(-1)), then held in water containing copper sulfate. After 8 h the mortality of L. garvieae-exposed prawns held in water containing 0.4 mg l(-1) copper sulfate was significantly higher than prawns held in water containing 0.2 and 0.3 mg l(-1) copper sulfate. At the lower L. garvieae density, cumulative mortality of prawns increased directly with ambient copper sulfate concentrations in the range of 0.2 to 0.4 mg l(-1). All prawns survived a 168 h exposure to 0.1 mg l(-1) copper sulfate. Prawns exposed to different concentrations of copper sulfate were examined for hemocyte density, phenoloxidase activity and respiratory burst. No significant differences in hemocyte density were observed among treatments. In prawns following a 48 h exposure to 0.1 mg l(-1) copper sulfate, phenoloxidase activity was decreased, but respiratory burst was increased. In conclusion, copper sulfate increased the virulence of L. garvieae to M. rosenbergii and modulated its immune system. Copper sulfate at 0.1 mg l(-1) decreased susceptibility of M. rosenbergii to L garvieae infection, whereas at 0.2 mg l(-1) the susceptibility was increased. The generation of superoxide anion by M. rosenbergii exposed to copper sulfate at a concentration higher than 0.2 mg l(-1) was considered to be cytoxic.  相似文献   

12.
在饲料中添加0、30和50 mg Cu/kg饲料的蛋氨酸铜,投喂凡纳滨对虾(Litopenaeus vannamei)7、14和21d,检测对虾体组织铜蓄积、免疫相关基因(Toll受体mRNA和溶菌酶mRNA)表达水平和免疫抗菌能力的变化。结果表明:凡纳滨对虾肝胰腺铜含量随着饲料蛋氨酸铜添加量增加及投喂时间延长而显著增加(P0.05);对虾肌肉的铜含量显著低于肝胰腺的铜含量。饲料中铜水平对凡纳滨对虾肌肉、血淋巴及肝胰腺中溶菌酶活性无显著影响(P0.05)。对虾组织SOD活性因饲料中铜水平和投喂时间变化显著,添加30 mgCu/kg组对虾肌肉、血淋巴和肝胰腺中SOD活性在第21天时显著高于其他两组(P0.05)。饲料中铜水平对凡纳滨对虾鳃组织中溶菌酶mRNA表达水平无显著影响,但显著影响鳃组织Toll受体mRNA表达水平(P0.05)。第7天时凡纳滨对虾Toll受体mRNA表达水平随着饲料铜水平升高而显著升高(P0.05);第14和第21天时,Toll受体mRNA表达水平在摄食添加30 mg Cu/kg组最高。人工急性感染溶藻弧菌(Vibrioalginolyticus)实验表明,第7天时,摄食添加50 mg Cu/kg组凡纳滨对虾全致死时间和半致死时间长于未添加铜组和添加30 mgCu/kg组,但在第14天,摄食添加30 mg Cu/kg组的全致死时间和半致死时间最长。研究表明饲料铜添加水平不但影响组织中铜的蓄积,还影响凡纳滨对虾SOD活性和Toll受体mRNA表达水平,从而影响机体的抗弧菌能力。  相似文献   

13.
&#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &#  &# 《水生生物学报》2015,39(6):1126-1133
为了更全面理解日本沼虾(Macrobrachium nipponense)的铜/锌营养生理作用,研究利用RACE技术从日本沼虾肝胰腺中克隆获得一金属硫蛋白基因cDNA全长(mn-MT),并对该基因分子特征、组织表达谱和饲料铜/锌水平对其表达的影响进行分析。结果显示:(1)mn-MT cDNA全长665 bp,含编码59个氨基酸的180 bp的开放阅读框,预测该多肽的理论分子量为6.085 kD,等电点为7.73。该蛋白中半胱氨酸含量最高(30.5%),其次是赖氨酸(16.95%)和丝氨酸(10.17%)。相似性分析显示mn-MT氨基酸序列与美洲海螯虾、斑节对虾和中华绒螯蟹MT的相似性分别达到78%、75%和75%。(2)qRT-PCR分析显示, mn-MT mRNA在肝胰腺、血细胞、鳃、胃、卵巢、肠和肌肉中都有表达,其中肝胰腺中表达量最高。(3)用4组铜添加量分别为0、20、40及160 mg/kg的饲料和3组锌添加水平分别为0、35和210 mg/kg的饲料饲喂初重为(0.1010.002) g日本沼虾56d后,分析各组虾肝胰腺的mn-MT mRNA表达。mn-MT mRNA表达随饲料铜水平的提高而升高,到40 mg/kg组达到最高(P0.05),而后开始下降;饲料中高锌(210 mg/kg)显著提高mn-MT表达(P0.05), 0和35 mg/kg组间差异不显著(P0.05)。结果表明饲料中铜/锌均可影响mn-MT表达,且呈现不同的剂量依赖效应。    相似文献   

14.
The aim was to assess over 2 years the treatment efficiencies of vertical-flow wetland filters containing macrophytes and granular media of different adsorption capacities. Different concentrations of lead and copper sulfate (constant for 1 year each) were added to urban beck inflow water in order to simulate pretreated (pH adjustment assumed) mine wastewater. After 1 year of operation, the inflow concentrations for lead and copper were increased from 1.30 to 2.98 and from 0.98 to 1.93 mg/L, respectively. However, the metal mass load rates (mg/m(2)/d) were increased by a factor of approximately 4.9 for lead and 4.3 for copper. No breakthrough of metals was recorded. Lead and copper accumulated in the biomass of the litter zone and rhizomes of the macrophytes. Furthermore, microbiological activity decreased during the second year of operation. Bioindicators such as ciliated protozoa and zooplankton decreased sharply in numbers but diatoms increased. In conclusion, the use of macrophytes and adsorption media did not significantly enhance the filtration of lead and copper. Particulate lead is removed by filtration processes including straining. Furthermore, some expensive and time-consuming water quality variables can be predicted with less expensive ones such as temperature in order to reduce sampling costs.  相似文献   

15.
This experiment was conducted to examine the effect of dietary copper supplementation on somatostatin (SS) and growth hormone-releasing hormone (GHRH) mRNA expression levels in the hypothalami of growing pigs. A total of 45 crossbred pigs were randomly assigned to three groups of 15 pigs each; five replicates of three animals comprised each group. Pigs were allocated to diets that contained 5 mg/kg copper (control), 125 mg/kg copper sulfate, or 125 mg/kg copper methionine. At the end of the experiment, five pigs were selected at random from each group and slaughtered, and hypothalami were collected for determination of SS and GHRH mRNA expression levels. The results showed that the SS expression levels were lower and the GHRH levels were higher in pigs fed the diets with 125 mg/kg copper methionine (P < 0.05) and 125 mg/kg copper sulfate (P < 0.05), respectively, than in pigs fed the diet with 5 mg/kg copper. Furthermore, the relationship between SS mRNA and GHRH mRNA abundance had a significantly negative correlation (P < 0.05). The data indicated that high dietary copper could enhance GHRH mRNA expression levels and suppress SS mRNA expression levels in the hypothalami of pigs. High lever dietary copper (125 mg/kg copper sulfate or 125 mg/kg copper methionine) increased pigs’ growth performance and feed efficiency but had no significant effect on daily feed intake; 125 mg/kg copper sulfate or 125 mg/kg copper methionine at the same lever had no difference on growth promoting in pigs.  相似文献   

16.
Lembi  C.A. 《Journal of phycology》2000,36(S3):43-44
The major method for algae control in the U.S. is the application of copper. Certain groups of phytoplankton, such as the green algae, are known to be more tolerant to copper than groups such as the cyanobacteria. Through experience, commercial applicators suggest that mat-forming algae also differ in their susceptibility to copper, but to this point, data to support these observations have not been available. Laboratory studies in which unialgal cultures of mat-forming algae were exposed to a range of copper concentrations show a clear progression in copper tolerance. The EC50 values (concentration of copper in mg Cu L−1 that results in 50% reduction of biomass) were less than 0.003 ( Spirogyra, Oedogonium ), approximately 0.050 ( Hydrodictyon , Pithophora , Rhizoclonium ), and greater than 0.200 ( Oscillatoria ). These data are important to us in the midwest because Oscillatoria is becoming a more frequent component of mat-forming algae infestations. The Oscillatoria infestations are caused by at least five different species, each of which is very tolerant to copper. Circumstantial evidence suggests that the increasing frequency of this mat-forming cyanobacterium is due to elimination of more sensitive genera (such as Spirogyra or Rhizoclonium ) with heavy copper dosing. In addition to concerns often expressed about copper use, such as buildup in the sediments, toxicity to invertebrates, and possible (although not well verified) resistance of cyanobacteria, another compelling reason to seek alternative approaches to copper is the buildup of copper-tolerant mat-forming algae.  相似文献   

17.
A 2 x 2 x 3 factorial experiment was conducted to study the pH dependence of a silicon-iron interaction in vivo. The dietary treatments used in the factorial design were the following (mg/kg of diet): silicon, 0 and 500; iron, 35 and 187; acid-base, ammonium chloride as 0.5% of total diet (acidic), sodium bicarbonate as 1.0% of total diet (basic), or no supplementation of acid or base (control). The supplementation of 500 mg silicon/kg of diet increased plasma-iron concentration in rats fed the acidic or control diets, but not in rats fed the basic diet. A high dietary-iron level suppressed copper absorption and utilization and subsequently imposed a negative effect on its own utilization. An increase in the plasma total-cholesterol concentration caused by high dietary-iron level was likely a consequence of the antagonistic effect of iron on copper absorption and utilization. The use of cupric sulfate pentahydrate as the dietary-copper source in this study resulted in plasma copper concentrations that were approximately twice those obtained in a related study using cupric carbonate. Also, a 42% coefficient of variation (C.V.) for plasma-copper concentrations of rats fed cupric sulfate in this study was greatly reduced from the C.V. = 108% previously associated with the dietary cupric carbonate.  相似文献   

18.
Previous studies have shown the inhibitory effect of the in vitro application of copper sulfate on hippocampal long-term potentiation. While in vivo administration of copper did not affect spatial learning and memory. To find possible answers to this controversial issue, we evaluate the effect of different doses of copper sulfate on in vivo long-term potentiation, synaptic transmission, and paired-pulse behavior of CA1 pyramidal cells. Thirty-two male Wistar rats were divided into four groups: control, 5, 10, and 15 mg of copper sulfate. Field excitatory postsynaptic potential from the stratum radiatum of CA1 neurons was recorded following Schaffer collateral stimulation in rats. Spike amplitude, long-term potentiation and paired-pulse index were measured in all groups. The results of this study showed that 5 mg/kg copper sulfate increased synaptic transmission and inhibited long-term potentiation and decreased the hippocampal paired-pulse ratio, while 10 and 15 mg/kg copper sulfate did not affect CA1 synaptic transmission properties. Low, but not high, doses of copper sulfate affect synaptic plasticity. This finding may explain the difference between the effect of copper on synaptic plasticity and spatial learning and memory.  相似文献   

19.
SUMMARY: Because of the increased use of copper and galvanized pipes, samples of water for bacteriological examination not infrequently contain minute traces of copper or zinc. These metals have a fairly rapid bactericidal action in the sampling bottle. The bactericidal action of copper can be prevented by the thiosulphate used for neutralizing chlorine; 100 mg/l is a useful quantity for general use in all sampling bottles. The bactericidal action from zinc can be prevented by the use of a small quantity of sodium phosphate in the sampling bottle. When special sampling points are installed, copper or galvanized pipes should be avoided.  相似文献   

20.
Mortality and physiological tests following exposure to waterborne copper were performed in the red swamp crayfish Procambarus clarkii from a central Italian population. Mortality tests gave an estimated 96 h LC50 value (with 95% confidence limits) of 162 (132-211) mg L(-1) waterborne copper II. Variations in cardiac and ventilatory rates were simultaneously monitored using a non-invasive plethysmographic technique. In experiments with different sub-lethal copper concentrations (control, 0.5, 1 and 10 mg L(-1)) performed at different times (3, 6, 96 h), copper exposure elicited a reduction in both heart and scaphognatite rates. Following exposure to 10 mg L(-1) copper for 96 h, the heart and scaphognatite rates decreased to about 35% of the initial values. The reduction was fully reversible, since crayfish exposed to 0.5, 1 and 10 mg Cu L(-1) for 96 h resumed control rates after a 3-h residence in clean water. In crayfish pre-exposed (96 h) to sub-lethal copper concentrations (0.1 and 1 mg L(-1)) and then held in control water (3 h), the reduction of heart and scaphognatite rates after exposure to 10 mg Cu L(-1) were significantly lower than in specimens pre-exposed to control water. Therefore, copper induces a concentration and time dependent reduction of both cardiac and ventilatory activity in P. clarkii; these responses can be reduced or fully abolished by pre-exposure to sub-lethal levels of the metal.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号