17β－雌二醇诱导鲻鱼雌性化的机制：芳香化酶和雌激素受体双染定位研究

用免疫细胞化学双重染色技术和鼠抗人芳香化酶抗体、兔抗人雌激素α受体与β受体亚型(ER-α和ER-β)抗体、兔抗人雌激素(E2)抗体，对鲻鱼(Mugil cephalus)脑各部位进行定位研究。结果显示，芳香化酶和E2、芳香化酶和ER-α、芳香化酶和ER-β、ER-α和E2的双染免疫活性物质分布在鲻鱼嗅脑、大脑、间脑和小脑的神经细胞的胞核或胞质及其突起或神经纤维上。值得指出的是，鲻鱼下丘脑视前区芳香化酶免疫活性细胞上共存有雌激素α受体与β受体亚型，提示E2诱发鲻鱼雌性化的作用机制是，E2先与芳香化酶样神经细胞上的雌激素受体结合，而后激发与性分化相关的芳香化酶基因的表达。     

日本鳗鲡胃肠胰内分泌细胞的鉴别与定位

应用过氧化物酶标记的链霉亲和素(streptavidin-peroxidase简称S-P法)免疫组织化学技术，用抗5-羟色胺、生长抑素、胃泌素、β-内啡肽、胰高血糖素抗体对日本鳗鲡的胃肠胰内分泌细胞进行研究。结果表明：日本鳗鲡胃肠道各段均存在5-HT和Som免疫活性内分泌细胞。Gas细胞分布于胃体部、幽门部和前肠、中肠；胃贲门部和后肠未检出Gas细胞。β-内啡肽、Glu细胞在胃肠道各段均未检出。在胰腺中均鉴别出Glu细胞和Som细胞。     

GnRH及其受体在2种真骨鱼消化系统中存在的免疫细胞化学证据

用链霉亲和素—生物素化过氧化物酶复合物(strept avidin biotin—peroxidase complex，SABC)免疫细胞化学方法，使用促性腺激素释放激素(gonadotropin—releasing hormone，GnRH)，促性腺激素释放激素受体(gonadotropinreleasing hormone receptor，GnRHR)2种抗血清对黄颡鱼(Pelteobagrus fulvidraco)和鲇(Silurus asotus)的食道、贲门、胃底、幽门、前肠、中肠、后肠和胰中的免疫活性内分泌细胞进行了定位。结果表明：在鲇的食道、胃、肠、肠固有膜、肠肌间神经丛、胰腺和胰岛中均存在着GnRH和GnRHR免疫活性阳性反应；黄颡鱼消化系统中除了在食道和胰岛中未见GnRH和GnRHR的免疫活性阳性反应外，其他部位均有阳性反应，而且GnRH和GnRHR分泌细胞的分布模式相类似。说明胃肠道中GnRH分泌细胞可能以自分泌或旁分泌方式参与消化功能的调节。本研究首次证实在鱼类的消化系统中存在着GnRH及其受体的免疫活性内分泌细胞，可为GnRH功能的多样性等研究领域提供新的形态学依据。     

[07]5种胃肠激素样内分泌细胞在斜带石斑鱼稚鱼期消化道中的定位

应用免疫细胞化学SABC方法,用5-羟色胺(5-Hydroxytryptamine,5-HT)、生长抑素(Sonmtostatin,Som)、P物质(substance P,SP)、胃泌素(Gastrin,GAS)和神经肽Y(Neuropeptide,NPY)5种特异性哺乳类胃肠激素抗血清对斜带石斑鱼(Epinephelus coioides)稚鱼期的消化道进行免疫细胞化学定位.结果显示,5-HT-和Som-样免疫活性细胞定位在斜带石斑鱼稚鱼的胃各部,包括胃贲门部、胃体和胃幽门部;SP-、GAS-样免疫活性细胞则在胃和肠均存在,其中SP-样细胞定位在胃体部和胃幽门部以及整个肠道,GAS-样细胞则从胃幽门部至肠道各段均存在;NPY-样免疫活性细胞仅在肠道中被检测到.根据这5种胃肠激素样内分泌细胞的形态、染色强度及其分布,可判断其在稚鱼期已经发育成熟,已像成鱼胃肠激素内分泌细胞一样,调节消化道的运动和消化液的分泌.本研究结果提示,斜带石斑鱼稚鱼死亡的原因可能与其胃肠激素样内分泌细胞的功能没有直接关系.     

17-β雌二醇诱导鲻雌性化的机制

用原位杂交和免疫细胞化学技术,对服用17 β雌二醇实验组和对照组幼年鲻脑各部和性腺进行芳香化酶的定位。结果发现,芳香化酶转录物和特异性蛋白在幼年鲻端脑(嗅球和大脑)、间脑、中脑和小脑是丰富的。在性别未分化时,芳香化酶免疫活性细胞在幼鲻脑各部的分布密度有显著的差异。在嗅球,对照组芳香化酶免疫阳性细胞的分布密度高于实验组,而在间脑、中脑和小脑实验组免疫阳性细胞数量比对照组多1～3倍,特别是下丘脑视前区芳香化酶的免疫阳性细胞数量尤占优势,提示芳香化酶在幼年鲻性分化中可能起关键的作用。另外,在性分化后,芳香化酶免疫活性还定位在卵巢颗粒细胞和精巢间质细胞与足细胞。同时,免疫阳性物质也定位在卵巢和精巢的生殖细胞。这些结果揭示了17 β雌二醇诱发幼鲻雌性化的机制可能是通过芳香化酶的介导,本研究首次提供形态学新的证据。最后,文中还讨论了芳香化酶在鲻性腺发育中可能的生理作用。     

厦门杏林湾普通鲻鱼性腺组织学研究

本文报道了对厦门郊区封闭的海湾杏林湾普通鲻鱼性腺的组织学观察结果。观察结果表明，普通鲻鱼成熟系数变化周期和性腺发育情况相一致，首次成熟年龄为3岁，成熟时间在11、12月。杏林湾普通鲻鱼生长发育与美国的相似，而比地中海、黑海的同种鱼要快。普通鲻鱼大生长期卵母细胞吸收过程分三个阶段，从11月下旬开始，延续到翌年1-2月结束。大生长期的卵母细胞吸收过程主要依靠滤泡上皮细胞活性提高，产生分泌物质促进透明层、胶质层和卵母细胞内含物的分解，滤泡上皮细胞还直接吞噬卵黄颗粒。     

鲻在冷冻过程中蛋白质的变性

通过研究鲻在冷冻过程中Ca^2 -ATPase的活性、挥发性盐基氮和凝胶强度的变化,为鲻鱼的冷冻加工提供理论依据。结果表明,抗冻剂能有效地抑制鲻于在冷冻过程中Ca^2 -ATPase活性的下降,同时能提高鲻鱼糜的凝胶强度且防止鲻鱼糜在冷过程中凝胶强度的下降。抗冻剂在鲻鱼冷冻加工中的应用是行之有效的。     

我国台湾省鲻鱼人工繁殖技术概述

自六十年代开始，台湾省经过10年的刻苦研究，鲻鱼人工繁殖苗种获得成功。其经验在一定程度上带动和推动了国内外鲻鱼人工繁殖技术研究的开展。特别是对鲻鱼亲鱼的培育、激素诱导及仔鱼培育等方面，具有一整套完整的经验。为了借鉴他们的经验。以推动我国其它地区开展鲻鱼人工繁殖技术的研究，现将台湾鲻鱼人工繁殖技术概述如下。     

蛇鲻冰藏和冻藏过程中鲜度指标的变化以及高压处理对其凝胶形成能的影响

研究了蛇鲻(Saurida wanieso)冰藏和冻藏过程中K值、挥发性盐基氮(TVBN)、Mf Ca^2 -ATPase全活性等鲜度指标的变化,并研究了高压加工法制备对蛇鲻鱼糕凝胶形成能的影响。结果表明：冰藏过程中鲻鱼的鲜度急剧降低,其货架期仅为10d左右,冻藏过程中蛇鲻保藏90d,鲜度缓慢降低。随着K值和TVBN的增加,鲻鱼的凝胶形成能降低,Mf Ca^2 -ATPase全活性与凝胶形成能关系不明确。通过加热处理,冰藏和冻藏的蛇鲻能保持正常凝胶形成能的时间分别为6d和60d,而高压处理蛇鲻能保持正常凝胶形成能的时间分别为至少14d和90d,高压处理能够显著提高蛇鲻的凝胶形成能从而延长其可利用期限。     

养殖条件下鲻鱼生长发育的初步研究

鲻鱼（Mugil cophalus Linnaeus）是鲻科鱼类中分布最广且最早被人类利用及研究的对象之一，其个体大、生长快、抗病性强、食物链级次低，可在淡水、半咸水及海水中正常生长。有关鲻鱼生长发育的研究，国内外学者已做了不少工作。鲻鱼的生长情况与鲻鱼养殖的经济效益有着直接的关系，同时也影响到鲻鱼性腺的发育，关系到鲻鱼人工繁殖工作的研究。     

Gut hormones in cyclostomes

The current state of knowledge about regulatory peptides in endocrine cells and nerves of the alimentary canal of lampreys and hagfishes is reviewed. Cyclostomes have a wide range of peptides similar immunochemically to those of higher vertebrates. They include, in the endocrine cells of the intestine, peptides resembling glucagon, gastrin/cholecystokinin, peptide YY (pancreatic polypeptide/neuropeptide Y), substance P, vasoactive intestinal peptide, somatostatin and, in the larval stages at least, insulin. The enteric nerves of some lamprey species contain peptides resembling bombesin (gastrin-releasing peptide) and calcitonin gene-related peptide, as well as serotonin. The occurrence of other peptides is less well documented. Little is known of the molecular structure or the biological roles of the enteric peptides in cyclostomes. Extraction, purification, sequencing and physiological experiments are greatly needed.     

野生鲻鱼和养殖鲻鱼消化系统的组织学观察

野生与养殖鲻鱼(Mugil cephalus)的消化系统在形态和组织结构上存在一定差异.(1)形态方面:食道粗而短,胃呈球形,包括贲门部、盲囊部、胃体部和幽门部4个区域,胃与肠相接处有2个指状幽门盲囊,肠道在腹腔内盘旋5圈.肝脏黄褐色,右叶较左叶大,未发现独立的胰脏.养殖鲻鱼消化道周围包裹更多脂肪,胃较小但胃腔更大,肠...     

Effects of vasoactive intestinal polypeptide,substance P, 5-hydroxytryptamine,met-enkephalin and neurotensin on the swimbladder smooth muscle of two teleost species,Gadus morhua andAnguilla anguilla

The effects of vasoactive intestinal polypeptide (VIP), substance P (SP), 5-hydroxytryptamine (5-HT), neurotensin (NT) and met-enkephalin (mEnk) on the smooth muscles of the teleost swimbladder were studied in two teleost species, the Atlantic cod (Gadus morhua) and the eel (Anguilla anguilla). The study was made on isolated strip preparations of the muscularis mucosae, using putative transmitters corresponding to the immunoreactive materials that have previously been localized by immunohistochemical methods in nerves or endocrine/paracrine cells of the teleost swimbladder and/or the gastrointestinal canal. VIP was relaxatory on both cod and eel swimbladder smooth muscle, SP and 5-HT were constrictory in both species, and mEnk was excitatory on the eel swimbladder smooth muscle. Clear effects of these agents were usually seen at a concentration ofca. 10 nM in cumulative concentration/effect experiments. NT had no effect in either species. In the eel, the effects on the pneumatic duct were generally greater than on the swimbladder proper. The study indicates that the 5-HT and peptides previously observed by immunohistochemistry have physiological functions in the swimbladder.     

6 种胃肠激素样内分泌细胞在细鳞鲑消化道的定位

采用免疫细胞化学ABC方法,选择5-羟色胺(5-hydroxytryptamine,5-HT)、生长抑素(somatostatin,SS)、胰多肽(pancreatic polypeptide,PP)、胃泌素(gastrin,GAS)和P物质(substance P,SP)6种特异性哺乳类胃肠激素抗血清,对不同年龄段(1龄、2龄和3龄)细鳞鲑(Brachymystax lenok)的消化道内分泌细胞进行了免疫细胞化学定位研究.结果表明,仅在食管、胃贲门、胃体和胃幽门检出有5-HT、SS和PP阳性细胞的分布(除1龄鱼食道),且这3种内分泌细胞均大量定位于胃部;在前肠、中肠、后肠和直肠中均未检测到这3种内分泌细胞的阳性反应.在3个年龄段的细鳞鲑胃肠各部位均未检测到GAS、GLU和SP阳性细胞.细鳞鲑的5-HT、SS和PP与其他有胃鱼类的内分泌细胞一样,可分为2种类型,即开放型和闭合型,这类细胞主要通过腔分泌和旁分泌两种方式释放激素.5-HT、SS和PP这3种细胞在1龄幼鱼消化道内就已经发育成熟,其对胃肠道活动的调节作用已经与成鱼没有差别,细胞的分布密度随着细鳞鲑的年龄增长不断增加.本研究揭示了不同生长阶段细鳞鲑消化道中这6种胃肠激素内分泌细胞的发育特征,并阐明了这些胃肠激素细胞在细鳞鲑幼鱼消化道的分布、形态以及生理作用.     

Molecular tools for studying puberty in the grey mullet, Mugil cephalus: cloning of cDNAs that regulate reproductive function

The cDNAs coding for the brain GnRHs (AY373449-51), pituitary GH, SL and PRL, and liver IGFs (AY427954-5) were isolated. Partial cDNA sequences of the brain (Cyp19b) and gonadal (Cyp19a) aromatases have also been obtained. These tools would be utilized to study the endocrine regulation of puberty in the grey mullet.     

Study on cryogenic preservation of grey mullet sperm

Preliminary techniques of mass propagation of grey mullet were established in Taiwan some years ago. Among the many problems concerned, the cryogenic preservation of grey mullet sperm has been studied since 1971. The aim of this study is not only to ensure the availability of mullet semen anywhere and anytime it is needed, but also to contribute to the international cooperation of cross breeding of grey mullet in the future. Results of the study on cryogenic preservation of grey mullet sperm made during the experimental mass propagation of mullet in the Tungkang Marine Laboratory for the past 3 years are summarized in this paper.The gonadosomatic index (GSI) of male grey mullet migrating near the coast of Tungkang ranged from 4 to 20 during the spawning season. The pH value of the semen was 7.4. Each spermatozoon was composed of a head part measuring 2.3 μ × 1.4 μ and a tail part four to five times as long as the head. There were about 5.3 × 10¹⁰ sperms in each ml of semen. Eosin-nigrosin staining was used for clearer identification. Sperm motility was preserved for up to 23 days in the case of raw semen at 5° C. Cryoprotective agents were needed at the ultra-low temperature (?196° C) of preservation in liquid nitrogen. Feasible procedures of freezing the grey mullet sperm were determined. Fresh semen diluted with cryoprotective agents was dispensed into 0.5 ml straws which were then sealed. These pretreatments prior to cryopreservation had to be done within the correct equilibration time of 1 h or less. Semen in straws was precooled in liquid nitrogen vapor until a temperature of ?80° C was reached. Straws in the canister were then put into liquid nitrogen for long-term preservation. The optimum effect of cryoprotective agents was found with 5–10% glycerine or dimethylsulfoxide (DMSO) at 1:1, 1:5, and 1:10 dilutions. In this condition, both good motility and fertility before freezing and cryoprotection were obtained. So far the best result of frozen thawed mullet sperm was moderate motility and 2.7% fertility of the semen cryopreserved for 1 year and 4 days.     

中华鳖胃肠胰内分泌细胞的鉴定与定位

应用过氧化物酶标记的链霉亲和素（Streptavidin-peroxidase简称S－P法）免疫组织化学技术，用抗胰高血糖素、胃泌素、生长抑素、5－羟色胺抗体对中华鳖（Trionyx simensis）的胃、肠、胰内分泌细胞进行研究，结果表明：5－HT细胞在消化道各段均有分布，以小肠密度最高，胃、大肠、直肠其次，食管最少。Som细胞在胃底部、幽门部和小肠各段密度较高，胃贲门部、大肠和直肠密度较低。Gas细胞分布于胃体部、幽门部和小肠各段；胃贲门部、大肠和直肠未检出Gas细胞。Glu细胞在消化道各段均未检出，在胰腺中均鉴别出Glu细胞和Som细胞。     

Immunohistochemical detection of neuromodulators in the intestine of Salmo trutta L. naturally infected with Cyathocephalus truncatus Pallas (Cestoda)

Pathological and immunohistochemical investigations were carried out on the middle intestine of uninfected and parasitized brown trout, Salmo trutta L., from the Ceresone Channel in North Italy. Eighty-six brown trout were sampled by electrofishing, and 32 (37.2%) were infected with Cyathocephalus truncatus Pallas, 1781 (Cestoda). The intensity of infection ranged from 1 to 82 parasites per host and the most infected segments were the anterior (near the pyloric caeca region) and the central part of the middle intestine. Immunohistochemical tests were applied on sections of intestinal tissue of healthy and infected fish, and the presence of substance P (SP), calcitonin gene related peptide (CGRP), met-enkephalin, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY) and serotonin (5-HT) was documented. Endocrine epithelial cells of the tunica mucosa were positive to SP-, CGRP-, met-enkephalin-, and NPY-like peptides and 5-HT antisera; moreover, a higher number of these cells were recorded in the intestine of infected trout in comparison to uninfected fish. In addition, in parasitized S. trutta , SP-like and 5-HT immunoreactivities were found in likely immuno-related cells of the tunica propria-submucosa. Nerve cell bodies and terminals in the myenteric plexus were immunoreactive to almost all the tested peptides and 5-HT antisera. These data provide evidence for the role of the neuroendocrine system of S. trutta in the modulation of inflammatory responses to C. truncatus . Results are discussed with respect to a peptidergic involvement and host immune response to an intestinal tapeworm.     

Incorporation and metabolism of14C-labelled polyunsaturated fatty acids in wild-caught juveniles of golden grey mullet,Liza aurata,in vivo

The incorporation, and the capacity for desaturation and elongation in vivo, of intraperitoneally-injected,¹⁴C-labelled n-3 and n-6 C₁₈ and C₂₀ polyunsaturated fatty acids (PUFA) were investigated in juvenile golden grey mullet,Liza aurata. The results indicate that juvenile mullet have only limited ability to convert C₁₈ polyunsaturated fatty acids to C₂₀ and C₂₂ highly unsaturated fatty acids (HUFA)in vivo. This suggests that juvenile golden grey mullet require the provision of preformed C_20/22 HUFA, such as eicosapentaenoic and docosahexaenoic acids, in the diet. The impairment in the desaturase/elongase pathway was similar to that found in turbot,Scophthalmus maximus, and gilthead sea bream,Sparus aurata, being primarily at the level of Δ5-desaturase. The data from the largely herbivorous golden grey mullet juveniles are consistent with the hypothesis that marine fish in general, irrespective of dietary habits, have limited capacity for the desaturation and elongation of C₁₈ PUFA. The defect in Δ5-desaturase activity combined with the consistent finding that arachidonic acid is selectively incorporated and retained in membrane phosphatidylinositol suggests that, like turbot and gilthead sea bream, golden grey mullet may also have a requirement for preformed arachidonic acid in the diet.     

Kudoa trifolia sp. n. - molecular phylogeny suggests a new spore morphology and unusual tissue location for a well-known genus

A new species of myxozoan, Kudoa trifolia sp. n., was found in various organs of the golden grey mullet, Liza aurata (Risso), and the thinlip mullet, L. ramada (Risso), from the western Mediterranean. Spores developed in subspherical plasmodia of 0.28-1 mm diameter within connective tissue, predominantly in the spleen, the outer wall of the gall bladder and the gut, the mesenteries and occasionally also in the gills. The spores of K. trifolia differ from the commonly known shape of Kudoa by considerable enlargement of one of the four valve cells, thus forming a 'spore body', which contains the major part of the binucleate sporoplasm. Scanning electron microscopy of the spores revealed the presence of grape-like appendages, which occur in bundles terminally on the valve cells. Phylogenetic analysis based on the 18S rDNA sequence of K. trifolia showed that this species is deeply embedded in the genus Kudoa despite its aberrant morphology and host tissue location. This suggests important amendments to the morphological diagnosis of the genus Kudoa.