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1.
为了探讨三氯生(TCS)对雌性鱼类性激素的影响及其机制。通过半静态水质接触染毒法对雌性黄河鲤进行染毒,设置对照组和三个不同浓度组(0.04 mg/L、0.08 mg/L、0.16 mg/L)的TCS处理组,采用酶联免疫(ELISA)和实时荧光定量PCR(RT-PCR)法检测各组雌性黄河鲤血清睾酮(T)和雌二醇(E2)的分泌水平及其卵巢中促性腺激素释放激素(CGnRH-ii-2)和雌激素受体(Er)的mRNA表达水平。结果显示：各浓度组的T水平无显著性差异(P>0.01),而0.16 mg/L的TCS能使黄河鲤血清中的E2含量及E2/T显著性升高(P<0.05, P<0.01);TCS各浓度组卵巢中CGnRH-ii-2 mRNA水平显著下降(P<0.01),而0.08和0.16mg/L的TCS处理组Er mRNA水平显著升高(P<0.05,P<0.01)。结果表明：TCS具有潜在雌激素效应,其机制与雌激素受体和促性腺激素释放激素基因表达调控相关。 相似文献
2.
为了探讨三氯生(TCS)对硬骨鱼类性腺损伤作用的分子机制,通过半静态水体暴露法对斑马鱼(Danio rerio)进行染毒,将斑马鱼暴露在2种不同TCS浓度(0.034 mg/L和0.068 mg/L)溶液中,同时设置空白对照组,42 d后,利用实时荧光定量PCR(RT-qPCR)技术,探究TCS对斑马鱼卵巢抗氧化及凋亡相关基因表达的影响。结果发现:与空白对照相比,SOD、CAT和GPx1a基因在0.068 mg/L TCS处理组表达水平显著下调,GPx1和MT-2基因在0.034 mg/L浓度组表达显著上调;Bcl-2基因在0.068 mg/L浓度组表达显著下调,p53基因在0.034 mg/L浓度组表达极显著上调,Bax在TCS处理组中均显著上调。以上研究结果表明:较高浓度TCS显著影响了斑马鱼卵巢抗氧化和凋亡相关基因的表达,从而产生了氧化损伤和加速细胞凋亡的发生。 相似文献
3.
为探讨三氯生(TCS)对鱼类非特异性免疫及生长因子的影响,实验通过半静态水质接触染毒法对雄性黄河鲤(Cyprinus carpio)进行处理,设置对照组和三个不同浓度TCS处理组(0.04、0.08、0.16 mg/L),暴露42 d后,采用实时荧光定量PCR(RT-q PCR)法检测各组雄性黄河鲤肝胰脏中谷胱甘肽还原酶(GSR)、谷胱甘肽-S-转移酶-A(GSTA)、谷胱甘肽过氧化物酶(GPx)、促生长素(GH)及其促生长因子(IGF-1)mRNA相对表达量。结果显示:各浓度TCS暴露组的肝胰脏中GSR、GSTA及GH mRNA表达量显著下降,GPxmRNA表达量仅在0.08 mg/L的TCS处理组显著性降低;而IGF-1 mRNA表达量在TCS各处理组显著性升高(P0.05)。结果表明,TCS能够干扰雄性黄河鲤抗氧化酶及生长相关基因的mRNA表达。 相似文献
4.
为探究三氯生(TCS)对于硬骨鱼类的凋亡相关基因表达的影响,以雄性斑马鱼(Danio Rerio)为试验动物,采用半静态水体接触染毒法,将斑马鱼分别置于质量浓度为17、34和68μg/L的TCS溶液中,并设计空白对照组,42 d后,对鳃组织进行采样,利用普通PCR和RT-qPCR技术分析雄性斑马鱼鳃组织凋亡基因Bcl-2、Bax、MDM2、p53的表达量。研究发现,与空白对照组相比,Bax和p53基因在TCS处理组中的表达量都出现了下调趋势,且在68μg/L的TCS处理组中表达水平显著下调;Bcl-2在各TCS处理组中无显著变化;MDM2基因在34μg/L和68μg/L TCS处理浓度组中表现为极显著上调。研究结果表明:高浓度TCS对雄性斑马鱼鳃组织凋亡相关基因的表达具有一定的影响。 相似文献
5.
壬基酚对雌鲫受体表达和雌二醇水平的影响 总被引：1，自引：0，他引：1
研究了环境激素壬基酚（4-NP）在雌鲫体内的对雌激素受体的表达和雌二醇水平的影响。雌鲫腹腔注射1、50、100 mg·kg-1的4-NP或1 mg·kg-1的E2，分别在24 h和48 h提取肝脏RNA用RT-PCR查看α型雌激素受体（ER-α）和CYP1A的表达情况和提取血清用荧光免疫法测定E2浓度。结果表明：1 mg·kg-1 E2 处理组的ER表达在24 h和48 h有显著性增加（P<0.01）。1 mg·kg-1 4-NP处理组在24 h ER表达与对照组比较有极显著性增加（P<0.01），在48 h有显著性增加（P<0.05），E2浓度在24 h与对照组比较有显著性下降（P<0.05），但在48 h后有所回升；CYP1A表达在处理后24 h有显著上调（P<0.05），在48 h后有极显著上调（P<0.01）。50 mg·kg-1 4-NP处理组在24 h ER表达与对照组比较有极显著性增加（P<0.01），在48 h有显著性增加（P<0.05），E2浓度在24 h和48 h与对照组比较有极显著性下降（P<0.01）；CYP1A表达在处理后24 h有显著上调（P<0.05），在48 h后有极显著上调（P<0.01）。100 mg·kg-1 4-NP处理组ER表达在24 h和48 h与对照组比较有极显著性增加（P<0.01），E2浓度在24 h与对照组比较有显著性下降（P<0.05），在48 h有极显著性下降（P<0.01）；CYP1A表达有极显著上调（P<0.01）。随着4-NP注射量的增加，ER表达也逐渐增加，而E2浓度逐渐减少。ER表达上调效应：E2>100 mg·kg-1 4-NP >50 mg·kg-1 4-NP >1 mg·kg-1 4-NP，100 mg·kg-1的4-NP对ER表达的上调效果接近于1 mg·kg-1E2的效果。E2下降效应：100 mg·kg-14-NP >50 mg·kg-1 4-NP>1 mg·kg-1 4-NP。NP对CYP1A表达有上调作用，并且表达随注射浓度上升而增强（具剂量-依赖效应）。以上结果表明,4-NP具有弱雌激素样效应，并且能抑制鲫鱼血清中E2的水平并使ER表达上调，为4-NP在鲫鱼体内通过ER途径实现内分泌扰乱效应的可能性提供了支持。图2表1参30 相似文献
6.
以氯化镧(LaCl3?7H2O）为试验毒物,以稀有鮈鲫（Gobiocypris rarus）为试验材料,采用21 d慢性毒性试验（La3+含量分别为0.00、0.04、0.08、0.16、0.32、0.80 mg/L）,通过检测稀有鮈鲫肝胰脏中超氧物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量,研究了镧暴露胁迫对水生动物抗氧化系统的影响,以期从抗氧化生理响应的角度探讨稀土元素镧对水生动物的毒理机理。结果显示,与对照组相比,0.04～0.32 mg/L试验组肝胰脏SOD活性出现一定程度降低(P＞0.05),但0.80 mg/L组SOD活性出现一定程度上升(P＞0.05);0.04～0.32 mg/L试验组肝胰脏CAT活性较对照组出现一定程度降低(P＞0.05),但0.80 mg/L组CAT活性出现一定程度上升(P＞0.05),且0.80 mg/L组CAT活性显著高于0.04～0.32 mg/L组(P＜0.05);0.04～0.16 mg/L试验组肝胰脏MDA含量较对照组出现一定程度降低(P＞0.05),0.32mg/L组MDA含量略微升高(P＞0.05),0.80 mg/L组MDA含量显著高于对照组(P＜0.05),也显著高于其它La3+暴露组(P＜0.05)。研究表明,一定浓度的La3+暴露胁迫会对环境中水生生物抗氧化系统产生不利影响。 相似文献
7.
为评估十二烷基苯磺酸钠（SDBS）对黄颡鱼（Pelteobagrus fulvidraco）的毒性效应,在水温（24.5±0.3）℃下,将体质量（101.4±16.5）g的黄颡鱼饲养在流水充气的水泥池中,暴露于0.0 mg/L、0.2 mg/L、0.4 mg/L、0.6 mg/L和0.8 mg/L质量浓度的SDBS中10 d后,测定血清溶菌酶（LZM）、碱性磷酸酶（AKP）、肝胰脏超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性及丙二醛（MDA）、免疫球蛋白M(Ig M)和补体C3含量、总抗氧化能力（T-AOC）等,并用荧光定量PCR仪检测脾脏补体C3和CAT基因相对表达量。结果表明：SDBS暴露后黄颡鱼血清中的溶菌酶和碱性磷酸酶活性、补体C3和免疫球蛋白含量降低,肝胰脏的超氧化物歧化酶和过氧化氢酶活性及总抗氧化能力降低,而丙二醛含量升高。SDBS暴露后黄颡鱼脾脏中补体C3、CAT基因m RNA转录水平下调,在高浓度暴露组（0.8 mg/L）中补体C3基因m RNA转录水平显著下调（P<0.05）,在0.4～0.8 mg/L浓度暴露组中CAT基因m RNA转录水平显著下调（P&... 相似文献
8.
本研究利用Real-timePCR分析和比较sox9与amh基因在雄、雌虹鳟Oncorhynchus mykiss及及其伪雄鱼各组织中的表达模式。结果表明:sox9基因在这三种鱼性腺、脑、脾、肝以及脑垂体中的表达显著高于其他组织(P<0.05)。在性腺组织中,sox9基因在雄鱼中的表达量显著高于伪雄鱼(P<0.01),而在伪雄鱼中的表达量又显著高于普通雌鱼(P<0.01)。脑组织中,雌鱼sox9的表达显著高于雄鱼和伪雄鱼(P<0.05)。Amh基因在性腺和脑组织中的表达显著高于其他组织(P<0.05)。该基因在伪雄鱼性腺和脑中的表达均显著高于雄鱼和雌鱼(P<0.05)。结果表明,外源雄激素的诱导可导致伪雄虹鳟性腺和脑组织中sox9和amh基因的表达显著高于雌性虹鳟,促进其性腺的雄性化发育。本研究可为全雌性虹鳟制种技术研究奠定重要理论基础。 相似文献
9.
采用红细胞计数、白细胞分类计数等方法,研究了不同浓度亚硝酸盐（0mg/L、0.5mg/L、1.0 mg/L、2.0mg/L）和不同作用时间（24h、72h、120h、168h、264h）对草鱼鱼种外周血细胞的影响。结果表明：实验组草鱼红细胞数量明显低于对照组（P＜0.01）;2.0mg／L组红细胞数量最少,与1.0mg／L、0.5mg／L组差异极显著（P＜0.01）,1.0mg／L组与0.5mg／L组差异不显著（P＞0.05）;随着亚硝酸盐的作用时间延长,实验组红细胞数量逐渐减少,120h内变化明显。72h与24h比较差异显著（P<0.05）,120与72h差异极显著（P＜0.01）,120h、168h、264h之间差异不显著（P＞0.05）。镜检血涂片共观察到血栓细胞、嗜中性粒细胞、淋巴细胞和单核细胞等四种白细胞。实验组血栓细胞比例均低于对照组,并随亚硝酸盐的作用时间延长而逐渐下降,1.0mg／L与2.0mg／L浓度组草鱼血栓细胞比例接近,并低于0.5mg／L浓度组。实验组草鱼淋巴细胞、嗜中性粒细胞比例均高于对照组,并随亚硝酸盐的作用时间延长而逐渐上升,1.0mg／L、2.0mg／L浓度组草鱼淋巴细胞比例接近,并高于0.5mg／L浓度组;三个浓度组草鱼嗜中性粒细胞比例接近。实验组单核细胞均高于对照组,但由于比例较小,变化不明显。 相似文献
10.
汞离子暴露下草鱼肝胰脏过氧化氢酶活性动态变化 总被引：6，自引：0，他引：6
研究了暴露在不同汞离子浓度下的草鱼(Ctenopharyngodon idellus)肝胰脏过氧化氢酶(CAT)的活性变化。实验中汞离子浓度设5组,分别为0 mg/L、0.1 mg/L、0.3 mg/L、0.5 mg/L和0.7 mg/L,每组分别于1 d、5 d、12 d和21 d取样,测定肝胰脏过氧化氢酶活性。结果显示,0.1 mg/L组暴露1d时CAT活性显著低于对照组(P<0.01),然后增加,12 d显著高于对照组(P<0.01);在21 d时下降至正常水平。0.3 mg/L下暴露不同时间均显著高于对照组(P<0.01或P<0.05)。0.5 mg/L组和0.7 mg/L组在暴露1 d和21 d时酶活性显著高于对照组(P<0.01);5 d和12 d时与对照组之间未有显著差异。 相似文献
11.
Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
12.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
13.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
14.
15.
Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
16.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
17.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
18.
William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献
19.
Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide 总被引：1，自引：0，他引：1
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response. 相似文献
20.
Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献