Effect of thermal treatment on muscle tissue structure and ultrastructure of wild and farmed sea bass, <Emphasis Type="Italic">Dicentrarchus labrax</Emphasis> L

The present work studies the muscle tissue structure and ultrastructure in two populations: wild and farmed sea bass, Dicentrarchus labrax L., in both raw and cooked states. Results found in fresh raw muscle tissue ultrastructure of wild sea bass showed some typical early post-mortem alterations: fibre-to-fibre detachment, detachment of myofibrils to endomysium and swelling of mitochondria and sarcoplasmic reticulum, mainly. In cooked samples of wild and farmed groups, sarcolemma and endomysium were disrupted and coagulated in most of the zones. Myofibrils were detached from sarcolemma–endomysium. Electron-dense aggregates were observed in both subsarcolemmal and interstitial spaces. These granular aggregates also appeared close to sarcolemma and endomysium, like an electron-dense chain. The interstitial material was quantified in both groups, and it was more abundant in farmed than in wild specimens. The size of the cooked fibres was better preserved in wild than in farmed sea bass, which evidences a higher thermal resistance of muscle tissue in wild specimens.     

漂白粉蓄积对日本蟳4种组织超微结构的影响

根据急性毒性试验确定了漂白粉对日本蟳的安全质量浓度为0．6mg／L，采用透射电镜技术研究了该质量浓度下漂白粉蓄积对日本蟳4种组织细胞(肌肉、鳃、肝胰脏和心脏)超微结构的影响。试验结果表明：漂白粉主要损伤日本蟳的鳃和肝胰脏，其次是心脏，肌肉基本无损害。鳃细胞的损害表现为鳃丝水肿，细胞器溶解，角质层变薄，线粒体、内质网的肿胀、解体；肝胰脏细胞的主要损害特征为肝管微绒毛减少、线粒体水肿解体、内质网扩张、细胞核空泡化、核膜水肿、脂肪滴增加；心脏细胞的毒理变化为线粒体内嵴肿胀、瓦解，肌原纤维不规则，内质网溶解。安全质量浓度的漂白粉经16d蓄积后，虽没有导致日本蟳死亡，但已对其体内的鳃、肝胰脏、心脏等组织细胞的超微结构产生了不同程度的影响。     

漂白粉蓄积对日本昭示(虫寻)4种组织超微结构的影响

根据急性毒性试验确定了漂白粉对日本的安全质量浓度为0.6mg/L,采用透射电镜技术研究了该质量浓度下漂白粉蓄积对日本4种组织细胞(肌肉、鳃、肝胰脏和心脏)超微结构的影响。试验结果表明:漂白粉主要损伤日本的鳃和肝胰脏,其次是心脏,肌肉基本无损害。鳃细胞的损害表现为鳃丝水肿,细胞器溶解,角质层变薄,线粒体、内质网的肿胀、解体;肝胰脏细胞的主要损害特征为肝管微绒毛减少、线粒体水肿解体、内质网扩张、细胞核空泡化、核膜水肿、脂肪滴增加;心脏细胞的毒理变化为线粒体内嵴肿胀、瓦解,肌原纤维不规则,内质网溶解。安全质量浓度的漂白粉经16d蓄积后,虽没有导致日本死亡,但已对其体内的鳃、肝胰脏、心脏等组织细胞的超微结构产生了不同程度的影响。     

Early temperature effects on muscle growth dynamics and histochemical profile of muscle fibres of sea bass Dicentrarchus labrax L., during larval and juvenile stages

Recently, it has been found that the thermal experience during the earliest phases of development could determine the larval and postlarval growth characteristics of teleosts. In order to investigate the effects of the early temperature regime on the advanced stages of growth of sea bass, Dicentrarchus labrax L., this species was reared during the vitelline phase at two temperatures: natural temperature (15 °C) and 17.7±0.1 °C, and then larvae transferred to common temperature (natural temperature). Muscle growth was studied by morphometric and histochemical techniques (mATPase and NADH-TR). Body length and body mass were also measured. During the vitelline phase, muscle growth was similar in both experimental groups, but at 25 days, both hypertrophy and hyperplasia of white muscle fibres were greater in the prewarmed group (p<0.05). At the end of metamorphosis (80 days) and at 120 days, the average diameter of white muscle fibres, as well as the body length, were greater in the prewarmed group (p<0.05), but the number of white fibres did not differ significantly between groups. The morphological mosaic of white muscle fibres was observed at the end of metamorphosis, and the histochemical mosaic appeared gradually since the early postlarval stages. Thus, at 120 days, some specimens in both experimental groups showed three or four different mATPase staining white fibres: low (L), moderate (M), high (H) and/or very high (vH), whereas in other specimens, only L or M mATPase activity fibres were observed. Early T influenced the histochemical maturity of the white muscle. By 120 days, the proportion of H and vH fibres was greater in the prewarmed group (p=0.027; p=0.051, respectively). By 154 days, the four mATPase staining profiles (L, M, H, vH) were observed in all specimens of both groups, but the proportion of vH fibres was still higher in the prewarmed group. By 188 days, 3774 °C-day for the prewarmed group and 3759 °C-day for the natural temperature group, only slight differences between groups were observed in the histochemical properties and no differences were found in the number and size of white muscle fibres, neither in the body length and body mass of specimens.

In conclusion, a slight increase of temperature during the vitelline phase of sea bass increased the muscle growth and body length of fish in subsequent larval and postlarval stages, and advanced the histochemical maturity of the white muscle.     

长牡蛎精子膜蛋白的提取及其部分生化性质的研究

从提取时间和TritonX-100浓度两个方面对长牡蛎(Crassosstrea gigas)精子膜蛋白提取条件进行优化,确定最佳提取条件:将精液150 g离心去除精原细胞,经PBS缓冲液和Tris-HCl缓冲液清洗后,3 000 g离心10 min(4 ℃)得精子悬液;然后加入3倍体积含1% TritonX-100的膜蛋白提取液,冰浴振摇1 h;50 000 g离心15 min(4 ℃),收集上清液即为精子膜蛋白溶液.SDS-PAGE电泳后,考马斯亮蓝R-250染色检测到21种膜蛋白,分子量在26～156 kD之间,PAS染色检测到糖蛋白有14种,苏丹黑B染色检测到脂蛋白有17种,其中有13种膜蛋白既是糖蛋白又是脂蛋白.实验结果还发现1种分子量为38 kD的r16膜蛋白既为糖蛋白又为脂蛋白,且高碘酸-Shiff试剂和苏丹黑B染色最深,条带最清晰,蛋白丰度最高,与此相对的分子量为55 kD的r12膜蛋白,考马斯亮蓝R-250染色也较深,条带清晰,但其糖蛋白和脂蛋白染色相对r16膜蛋白较浅,说明r16和r12两种膜蛋白其蛋白丰度相差不大,其糖基化程度及脂化程度可能相差较大,此两种膜蛋白有待于进一步分离纯化.此研究结果可为长牡蛎精子膜蛋白在精子发生和受精过程中作用的研究提供基础资料.     

Oxidative status and histological changes in sea bass larvae muscle in response to high dietary content of docosahexaenoic acid DHA

In previous studies, we observed dystrophic alterations in muscle of 48‐day‐old sea bass fed imbalanced docosahexaenoic acid (DHA) and vitamin E diets. To understand the whole pathological process associated with oxidative stress, a histological study was performed by feeding 14‐day‐old sea bass larvae with microdiets containing different ratios of DHA/vitamin E (1/150, 5/150 and 5/300) for a period of 21 days. Larvae fed diet 1/150 showed no lesions in contrast to larvae fed diets 5/150 and 5/300 where the highest incidence of muscle lesions and thiobarbituric acid reactive substances (TBARS) content was observed. Semithin sections revealed focal lesions consisting of degenerated fibres with hypercontracted myofilaments and extensive sarcoplasm vacuolization affecting both red and white muscle. Ultrathin sections of degenerating muscle fibres showed diffuse dilatation of sarcoplasmic reticulum, disorganized myofilaments and autophagic vacuoles containing myelin figures and dense bodies. Additionally, some macrophages were observed among injured fibres as numerous satellite cells. Results from the study agree with those obtained from previous work, proving the pathological potential of free radicals in sea bass larvae musculature. Moreover, high vitamin E inclusion could not completely protect cell membranes from free radicals action.     

患“白体病”罗氏沼虾腹部肌肉病变的超微结构

取患“白体病”罗氏沼虾 (Macrobrachiumrosenbergii)腹部的病变组织及其鳃、心肌、肝胰腺、生殖腺等器官和组织 ,经光镜和电镜制样观察 ,未发现病原体 ,表明该病为非病原体引起的疾病。光镜下的病变组织结构与正常组织相比无明显异常。但在电镜下 ,病变主要表现为肌肉细胞的线粒体和肌质网的变性、坏死。线粒体肿胀、空泡化 ,肌质网增多且形成许多内陷小泡 ,表明细胞处于缺氧和钙代谢紊乱状态 ,这可能与虾生存的环境和养殖条件有关。根据超微病理与组织学观察结果 ,认为“罗氏沼虾白体病”更确切的命名应为“罗氏沼虾肌肉细胞线粒体坏死症”     

久效磷对中国对虾细胞超微结构的影响_I_对肝胰脏和肌肉的毒性效应

通过对０．１０ｍｇ／Ｌ久效磷处理的中国对虾细胞超微结构的透射电镜观察，结果表明：１．中毒的肝胰脏细胞内质网严重水肿、扩张、囊泡化，片层结构水肿；线粒体内嵴局部瓦解；肝管微绒毛出现空缺区域及药物中毒的退化结构；脂滴电子密度不匀。２．中毒的肌肉细胞肌原纤维萎缩、间隔增大，肌浆网水肿、扩张，部分肌浆网膜破裂，线粒体内嵴膨胀，细胞质中出现中毒坏死巢。     

硫酸铜蓄积对日本[虫寻]4种组织细胞超微结构的影响观察

通过蓄积毒性试验,研究了安全质量浓度（0．5mg·L^-1）下硫酸铜（CuSO4·5H2O）对日本[虫寻]（Charybdis japonica）4种组织细胞（肌肉、鳃、肝胰脏和心脏）超微结构的影响。结果表明,铜离子（Cu^2＋）蓄积主要损伤的组织是鳃和肝胰脏,其次是心脏和肌肉。鳃细胞的损害表现为鳃丝水肿,细胞器溶解,角质层变薄,线粒体、内质网的肿胀、解体;肝胰脏细胞的主要损害特征为肝管微绒毛减少,线粒体水肿解体,内质网扩张,细胞核空泡化,核膜水肿和脂肪滴增加;心脏细胞的毒理变化为线粒体内嵴肿胀、瓦解,肌原纤维不规则,内质网溶解。0．5mg·L^-1的CuSO4·5H2O经过16d蓄积后虽然没有导致日本[虫寻]死亡,但已经对其体内组织细胞的超微结构产生了不同程度的影响。     

Muscle fiber types,growth and development in the whole myotome of cultured Pacific bluefin tuna Thunnus orientalis

Following the successful development of Pacific bluefin tuna (PBT) aquaculture, it is of considerable importance to determine the muscle fiber types and their growth patterns for future development. Muscle fiber profiles of dorsal ordinary, lateral ordinary (LO) and dark muscles and their growth patterns in PBT from 3.0 to 54.3 kg body weight were studied. Muscle fibers were histochemically stained for NADH-diaphorase and myosin adenosine triphosphatase activity (mATPase), and immunohistochemically stained with S-58 slow-muscle myosin antibody. All muscle fibers in dorsal and LO muscles showed low NADH-diaphorase activity, and acid-labile (pH 4.0 or 4.3) and alkali-stable mATPase activity. In LO muscle adjacent to dark muscle, three intensities of mATPase activity were observed after acid pre-incubation at pH 4.5 or 5.0, and the activity was related to the muscle fiber diameter. In dark muscle, all small and some large fibers stained intensely for NADH-diaphorase activity, related to their high aerobic metabolism. The high-active fibers with NADH-diaphorase in dark muscle were positive for S-58 antibody. Some large fibers in dark muscle showed intermediate NADH-diaphorase activity and high mATPase activity after alkali pre-incubations. These are fast-twitch oxido-glycolytic fibers in dark muscle and transformed to red muscle fibers with increasing body weight.     

The study on the cytology and histochemistry of lymphoid organ spheroids in Penaeus chinensis

The lymphoid organ spheroids (LOS) were investigated by cytological and histochemical techniques in Penaeus chinensis. The results showed that the LOS only appeared in the individuals with relatively large lymphoid organ (long diameter>2 mm.). The LOS were mainly made up of two types of cells, one of which had a low cytoplasm to nuclear volumetric ratio, developed marginated chromatin and 1–2 nucleoli, while the other had large cytoplasm to nuclear volumetric ratio, homogeneous chromatin, and no or only one nucleolus. These two kinds of cells all contained mitochondria and rough endoplasmic reticulum. The necrotic cells could usually be observed. The LOS showed negative PAS reaction, weak positive phenoloxidase, and negative -naphthyl-acetate esterase (-NAE).     

Myofibrillar proteins in white muscle of the developing African catfish Heterobranchus longifilis (Siluriforms, Clariidae)

Developmental changes in myofibrillar protein composition were investigated in the myotomal muscle of the African catfish, Heterobranchus longifilis (Clariidae), by several electrophoretic techniques. The main muscle fibres of larvae and the fast-white muscle fibres of juvenile and adult fish were found to express distinct myosin heavy chain and myosin light chain 2 (LC2) isoforms. Three myosin LC2 chains were successively detected, differing by their isoelectric points. In contrast, the alkali light chains remained qualitatively and quantitatively unchanged during fish growth. Actin, -tropomyosin, and troponin-C (TN-C) were also similar in larval, juvenile, and adult white muscle, but an additional larval tropomyosin isoform was found in the first developmental stages. Two isoforms of troponin-T (TN-T) and troponin-I (TN-I) were synthesised in the course of fish growth. Transition from the larval to the adult isoform was much faster for TN-T than for TN-I. Slow-red muscle myofibrils from adult H. longifilis showed no common component (except actin) with larval, juvenile, or adult fast-white muscle myofibrils. Red myofibrils displayed a single TN-T and a single TN-I isoform, but two isoforms of TN-C. The myofibrillar protein isoforms synthesised at any given developmental stage almost certainly reflect changes in the functional requirements of swimming muscles in the course of fish development.     

中华绒螯蟹肝胰腺白化症组织病理变化

采用常规石蜡切片技术和透射电镜技术,对患有肝胰腺白化症的中华绒螯蟹病变组织和细胞进行观察。发现病蟹肝胰腺、鳃、肌肉等组织细胞发生了不同程度的病变,其病理特征为肝细胞水肿、变性、坏死,细胞中脂肪颗粒锐减,线粒体水肿、嵴消失、形成空泡,内质网、溶酶体解体成小泡。鳃组织增厚,上皮细胞微绒毛排列疏松、不规则,部分线粒体嵴消失,出现膜性退化。坏死的肝细胞和鳃上皮细胞中出现细菌颗粒。肌细胞的病变主要表现为细胞核固缩,肌丝松驰、水肿、断裂、肌质网溶解形成小泡。中华绒螯蟹具有重要生理功能的肝胰腺、鳃组织发生了严重病变,使其功能损伤,不耐运输;而肌肉的松驰、肝胰腺脂肪的锐减影响了中华绒螯蟹的品质。同时,病变组织和细胞中未见病毒等生物病原,表明该病为非生物性疾病。图2表0参12     

日本沼虾中肠腺细胞的超微结构研究

应用电镜技术研究了日本沼虾中肠腺细胞的类型及超微结构。结果表明：日本沼虾中肠腺上皮细胞大多呈柱状，顶端具有微绒毛，依结构和功能不同可分为Ｒ细胞、Ｆ细胞、Ｂ细胞和Ｅ细胞４种类型。Ｒ细胞具有吸收、贮存营养物质的功能，细胞内含有脂滴、糖原和吞噬咆，内质网、线粒体等细胞器数量少；Ｆ细胞内蛋白酶原合成活动旺盛，粗面内质网极为发达，在数量上比Ｒ细胞多，几乎充满整个细胞；Ｂ细胞微绒毛较短，以胞饮方式吸收营养，在     

文蛤消化道粘液细胞研究

运用组织学和组织化学染色方法,在光镜水平上研究了文蛤消化道粘液细胞的类型,分布与组化特性。H.E染色法显示,粘液细胞主要存在于消化道上皮组织中,仅唇瓣结缔组织中发现有少量的粘液细胞,ABPAS染色法显示;文蛤消化道粘液细胞主要分为4种类型：Ⅰ型,呈红色,AB阴性,PAS阳性,含有中性粘液物质,Ⅱ型：呈蓝色,AB阳性,PAS阴性,含有酸性粘液物质;Ⅲ型：AB和PAS均呈阳性,但PAS阳性较强,两种粘液物质均含有,但中性粘液物质含量多;Ⅳ型：AB和PAS均呈阳性,但AB阳性较强,两种粘液物质均含有,但酸性粘液物质含量多,不同部位粘液细胞的类型,数量不同,唇瓣粘液细胞的数量较少,食道含有大量的粘液细胞,胃,肠,直肠中粘液细胞的数量以胃中最少,肠次之,直肠最多,AB-PAS（AB pH1.0）染色法显示：粘液细胞所含酸性粘液物质包括硫酸性粘液物质和涎酸性粘液物质,且唇瓣和直肠中粘液细胞所含的涎液酸性粘液物质比硫酸性粘液物质多,酶组化研究结果显示,肠粘液细胞具有弱酸性磷酸酶,弱碱性磷酸酶活性。     

Effects of urea and trimethylamine-N-oxide on ATPase of requiem shark myofibril and its constituents

ABSTRACT: The effects of trimethylamine- N -oxide (TMAO) on the urea-resistibility of requiem shark myofibrils were investigated, using Ca²⁺- and Mg²⁺-ATPase activities as a parameter. Both activities were hardly changed or activated up to 0.6 M urea. In contrast, the two activities both decreased to less than 50% in the presence of TMAO up to 0.5 M. When measured at a 2 : 1 molar ratio of urea and TMAO, Ca²⁺- and Mg²⁺-ATPase activities were similar to those in the presence of TMAO alone, indicating that TMAO reduced the urea-resistibility of myofibrils. Myosin, the most abundant protein in myofibrils, from requiem shark exhibited the effects of urea and TMAO on its Ca²⁺-ATPase activity, which was primarily similar to those of myofibrils. However, Ca²⁺-ATPase activities in the coexistence of urea and TMAO for actomyosin reconstituted from requiem shark myosin and chicken F-actin were approximately average of those measured independently in the presence of either urea or TMAO alone. Carp myofibrils, reconstituted actomyosin and myosin, which were used as teleost references, all showed a tendency in the effects of urea and TMAO on Ca²⁺-ATPase activities that was similar to those of requiem shark counterparts.     

Effect of Temperature on Quality-Related Changes in Cod (Gadus morhua) During Short- and Long-Term Frozen Storage

Cod (Gadus morhua) was stored at eight temperatures (?10 to ?80°C) for 1 to 18 months, after which quality indicators were measured—including drip loss, water holding capacity, low field NMR spin-spin relaxation, color, amount of thiobarbituric acid reactive substances, and sarcoplasmic reticulum Ca2+-ATPase and lysosomal Cathepsin D activities. Results from samples stored up to 12 months showed no significant differences between ?30°C and lower temperatures. The NMR measurements, however, indicated some changes in the water distribution of samples stored at ?30°C for 12 or more months compared to storage at ?40°C or lower.     

不同倍性长牡蛎闭壳肌和精子的组织学和超微结构观察

以二倍体、三倍体、四倍体长牡蛎(Crassostrea gigas)闭壳肌和精子为研究对象, 采用石蜡组织切片、透射电镜和扫描电镜方法, 比较了 3 种倍性长牡蛎闭壳肌和精子的组织学特性及超微结构的差异。研究结果显示, 二、三、 四倍体闭壳肌组织的肌纤维都包含粗肌丝、细肌丝、肌膜、肌束膜、肌内膜、线粒体、囊泡、小管、细胞核、肌浆网等结构, 但三者的形态及超微结构不同, 其中三倍体闭壳肌线粒体直径、肌纤维直径、粗肌丝密度显著大于二倍体和四倍体, 肌纤维密度显著小于二倍体和四倍体。不同倍性精子的扫描电镜和透射电镜结果显示, 二、三、四倍体长牡蛎精子在组成结构上相似, 分别由头部、中段和尾部构成, 但不同倍性精子中各结构大小和线粒体数目不同。在长牡蛎精子头部长度、宽度, 顶体高度、宽度, 线粒体长度的测量分析中, 四倍体精子的头部、顶体以及线粒体显著大于二、三倍体。三倍体精子的头部和顶体显著大于二倍体, 但三倍体精子的线粒体大小与二倍体相比无显著差异。此外, 二、三倍体精子均含 4 个线粒体, 但在本研究中发现了二倍体精子含有 5 个(占比 1%)线粒体的特例。四倍体长牡蛎精子的线粒体数目不同, 含有 4 个(占比 46%)、5 个(占比 52%)、6 个(占比 2%)这 3 种情况。 该研究阐明了不同倍性长牡蛎闭壳肌及精子的组织学特性和超微结构, 为深入研究长牡蛎肌纤维生物学特性和精子繁育生物学提供了基础资料。     

盐度和干露对大竹蛏呼吸代谢相关酶的影响

为探讨盐度和干露两种胁迫对大竹蛏呼吸代谢酶活力的影响,在实验室条件下分别研究盐度胁迫(15、20、25、30、35)和干露胁迫(6、12、24、48h)条件下,大竹蛏乳酸脱氢酶、碱性磷酸酶和琥珀酸脱氢酶3种酶活力的变化规律。结果显示,当盐度逐渐升高时,碱性磷酸酶的活性呈降低趋势,当盐度为20时,酶活性最低,为0.043U/g,当盐度为25时,酶活性最高,为0.053U/g。盐度对琥珀酸脱氢酶和乳酸脱氢酶呈现波纹型的影响,在盐度为25时,琥珀酸脱氢酶活性较高,为0.401U/mg;盐度为25时,乳酸脱氢酶活性较高,为0.604U/g,盐度为20时,乳酸脱氢酶活性显著降低,为0.287U/g,盐度为35时,乳酸脱氢酶活性无显著变化。当干露时间逐渐延长,从整体变化情况来看,琥珀酸脱氢酶、碱性磷酸酶和乳酸脱氢酶这3种酶的活性逐渐降低,当干露时间达到48h,3种酶活性均达到最低,分别为0.197U/mg、0.020U/g和0.187U/g。说明盐度和干露胁迫对大竹蛏呼吸代谢酶活力有显著影响(P<0.05)。研究结果可为大竹蛏的人工养殖和运输提供参考。