长鳍篮子鱼消化道黏膜上皮的扫描电镜观察

采用扫描电镜观察了长鳍篮子鱼(Siganus canaliculatus)消化道黏膜上皮表面细微的结构特征。结果显示,长鳍篮子鱼食道黏膜为纵行黏膜褶皱,在褶皱上形成"V"字型次级褶皱,黏膜上皮表面具有许多分泌孔及较多腺体导管的开口,上皮细胞扁平,似鳞片状,连接紧密。胃黏膜褶皱呈绳状纵向排列,黏膜上皮表面有许多沟回,细胞之间有较多的胃小凹,在上皮表面可见有乳头状突起,未见有微绒毛;上皮细胞为五边形或六边形,无细胞间隙。肠黏膜分布着密集排列的肠绒毛,绒毛呈拇指状或扁平状,黏膜上皮表面呈脑回状,分布有许多分泌颗粒,细胞游离面分布着丰富的微绒毛,细胞为多边形、圆形、不规则形,有细胞间隙。幽门盲囊黏膜上皮的结构与肠道相似。本文探讨了黏膜上皮结构与功能的关系。     

版纳鱼螈消化道解剖学和组织学观察

对我国特有珍稀濒危两栖动物版纳鱼螈(Ichthyophis bannanicus)的消化道进行解剖和组织学观察.结果表明,版纳鱼螈消化道呈直管状,无盘曲;胃、肠分化明显,肠可分为十二指肠、空肠、大肠和直肠;黏膜上皮食管为复层柱状纤毛上皮,胃后段为单层柱状上皮,直肠为复层扁平上皮,其余均为复层柱状上皮;口咽腔黏膜含大量巨型杯状细胞,有单泡状颌间腺;食道中下段有团泡状食道腺;胃体部含大量单管状胃腺;十二指肠和空肠有单泡状肠腺,绒毛发达;口咽腔的黏膜下层不明显,食道和直肠的黏膜下层为疏松结缔组织,其余均为细密的结缔组织;肌层除口咽腔为骨骼肌外,其余均为内环外纵两层平滑肌,其中,在十二指肠和空肠的两肌层间有细密的结缔组织连接.     

乌梢蛇胃上皮的组织学研究

用光镜和电镜观察了乌梢蛇胃上皮的组织结构。结果表明,①胃表面上皮均为单层柱状上皮,上皮细胞上部充满电子密度较高的椭圆形或杆状黏液颗粒,PAS反应呈强阳性;②胃体及幽门区上皮分别内隐形成单管状的胃底腺和幽门腺,无贲门腺;③胃底腺腺管分颈部和颈下部,颈部上皮细胞充满电子密度较低的近圆形的黏液颗粒,PAS反应呈强阳性,颈下部上皮细胞均分泌酶原颗粒,PAS反应呈阴性;④幽门腺细胞中亦充满电子密度较低、近圆形的黏液颗粒,PAS反应呈强阳性;⑤胃腺上皮细胞之间和腺细胞基部有不同类型的内分泌细胞分布。本文认为,乌梢蛇胃的消化能力较弱,其胃的进化在爬行动物中处于较低等的地位。     

白鲟消化道形态学与组织学的初步观察

白鲟消化道具有肉食性鱼类的典型特征,其口咽腔结构既适合捕食又适合吞食与滤食水生动物。咽后消化道可分为食道、胃后行支、胃前行支、小肠、瓣肠、直肠与肛门。幽门盲囊似一致密器官,小肠与瓣肠连接处有一特殊淋巴器官,肛门两侧有腹孔。白鲟口咽腔被覆层扁平上皮,上皮内有味蕾分布。咽后消化道组织分层为粘膜(无粘膜肌层)、粘膜下层(小肠及瓣肠前部无)、肌层与外膜。粘膜上皮为单层柱状上皮,由纤毛柱状细胞、一般柱状细胞和杯状细胞组成,其间还散在有颗粒细胞和游走细胞。食道后部与胃的一般柱状细胞为分泌粘液的细胞,肠内的一般柱状细胞为吸收细胞。胃后行支及部分前行支固有膜内有消化腺,其余各部的固有膜为致密层。小肠前中部粘膜形成蜂窝状粘膜窦,无肠腺。除食道前部肌层中有横纹肌外,其余部的肌层均为平滑肌。外膜内结缔组织有的致密有的疏松,外膜表面细胞柱状或立方形或扁平。     

Bax、TGF-β和Ghrelin在饥饿后长耳鸮胃及小肠中的免疫组织化学

应用免疫组织化学方法检测了Bax蛋白、TGF-β(TGF-β2、TGF-β3)和Ghrelin在饥饿后长耳鸮(Asio otus)胃及小肠中的表达,利用体视学方法对其表达强度进行半定量分析。结果表明,胃及小肠呈Bax、TGF-β2、TGF-β3和Ghrelin免疫反应阳性。Bax免疫反应阳性物质主要分布在胃黏膜、肠黏膜、肠腺的单层柱状上皮细胞,腺胃深腺单层立方上皮细胞及胃黏膜固有层;TGF-β2、TGF-β3免疫反应阳性物质主要分布在胃黏膜、肠黏膜及肠腺的单层柱状上皮细胞,腺胃深腺单层立方上皮细胞及肠黏膜固有层;Ghrelin免疫反应阳性细胞分布在腺胃深腺,十二指肠、空肠、回肠的黏膜、肠腺的单层柱状上皮细胞及黏膜固有层。Bax蛋白阳性表达部位的面密度值在腺胃有最大值,从腺胃到十二指肠面密度值下降,十二指肠到回肠逐渐上升;TGF-β2和TGF-β3阳性表达部位的面密度值在十二指肠达到峰值,TGF-β2从十二指肠到回肠阳性表达部位的面密度值呈递减趋势,TGF-β3从腺胃到十二指肠面密度值逐渐增大,之后下降,到回肠回升;Ghrelin阳性表达部位的面密度值从腺胃到回肠逐渐减小。Bax、TGF-β2、TGF-β3及Ghrelin在饥饿后长耳鸮胃和小肠各段均有不同程度的表达,它们可能参与长耳鸮胃肠功能的调节。     

乌梢蛇胃上皮的组织学研究

用光镜和电镜观察了乌梢蛇胃上皮的组织结构,结果表明,1胃表面上皮均为单层柱状上皮,上皮细胞上部充满电子密度较高的椭圆形或杆状黏液颗粒,PAS反应呈强阳性;2胃体及幽门区上皮分别内陷形成单管状的胃底腺和幽门腺,无贲门腺;③胃底腺腺管分颈部和颈下部,颈部上皮细胞充满电子密度较低的近圆形的黏液颗粒,PAS反应呈强阳性,颈下部上皮细胞均分泌酶原颗粒,PAS反应呈阴性;④幽门腺细胞中亦充满电子密度较低、近圆形的黏液颗粒,PAS反应呈强阳性;⑤胃腺上皮细胞之间和腺细胞基部有不同类型的内分泌细胞分布.本文认为,乌梢蛇胃的消化能力较弱,其胃的进化在爬行动物中处于较低等的地位.     

刀鲚幼鱼消化系统的组织形态学结构

采用光镜和扫描电镜观察长江刀鲚(Coilia nasus)幼鱼消化系统组织形态学结构。结果显示,刀鲚体长,口裂大,含有犬齿状的颌齿和尖锥状的腭齿,具有5对鳃弓,鳃耙长度明显大于鳃丝且表面附着不规则绒毛状细齿;胃呈"Y"型,胃与肠连接处具有16～21个指状环形幽门盲囊;肠为直肠,较短,比肠长为0.241±0.080;肝分为两叶,胰为独立的器官。刀鲚口咽腔为复层鳞状上皮,含有腺体、大量椭圆形黏液细胞、少量杯状细胞及味蕾;胃黏膜都为典型的单层柱状上皮,含有较多由上皮凹陷形成的胃小凹和胃腺;幽门盲囊具有20～25个丰富的褶皱,占满大部分幽门盲囊腔,黏膜层具有微绒毛;中肠黏膜上皮最发达,形成的褶皱细长且连接成网状,单层柱状上皮与复层扁平上皮交替分布。观察结果表明,刀鲚消化系统具有典型肉食性鱼类特征。     

圆尾鲎消化道组织结构与黏液细胞分布

利用石蜡切片、苏木素-伊红(H.E)和阿利新兰-高碘酸雪夫试剂(AB-PAS,AB,pH 2.5)组化染色技术研究圆尾鲎(Carcinoscorpius rotundicauda)消化道组织结构及其黏液细胞的分布特征。圆尾鲎消化道外形为一直管状,中肠部位有分支。H.E染色结果显示,食道、胃、幽门、中肠与后肠的管壁一般结构由外至内分为外膜、肌肉层、黏膜下层、黏膜层。食道是一段短管状结构,肌肉层较胃壁的薄但几丁质层极厚。胃则为一膨大的砂囊结构,内含一定数量的纵行黏膜皱褶,肌肉纤维排列整齐,几丁质层较薄。幽门与中肠套叠,幽门壁肌肉层很薄,几丁质层清晰可见。中肠和后肠结构差异不大,具有一定数量的黏膜皱褶,上皮细胞间分布比较多的黏液细胞,均无几丁质层。AB-PAS组化染色结果显示,消化道有Ⅰ和Ⅱ型两种黏液细胞,不同部位分布数量差别很大。食道和幽门未见黏液细胞。胃黏膜下层有少量Ⅱ型黏液细胞。中肠和后肠黏液细胞数量比较多,尤其是与幽门套叠的中肠前端区域,均以Ⅱ型黏液细胞为主,主要分布在黏膜下层和黏膜上皮。在后肠黏膜下层有Ⅰ型黏液细胞分布,而黏膜上皮则分布密集的Ⅱ型黏液细胞。圆尾鲎消化道组织结构及黏液细胞分布特征反映其不同部位功能的差别,体现食性与消化机能相协调的特点。     

银鲳消化道形态与组织学结构特征及其消化酶活性

为了解银鲳(Pampus argenteus)消化道结构特点与其功能及食性的相关性, 采用解剖、石蜡切片、AB-PAS染色及酶活性检测技术对银鲳消化道的形态、组织结构、黏液细胞分布及消化酶活性进行研究。结果显示, 银鲳的消化道由口咽腔(舌)、食道侧囊、食道、胃及肠构成, 胃肠交界处有很多幽门盲囊。食道侧囊呈椭球形, 食道粗短, 胃呈U型, 肠有多个盘曲, 肠指数为2.03。舌上皮内有少量味蕾及较多黏液细胞。食道侧囊、食道、胃及肠均由黏膜层、黏膜下层、肌层及浆膜组成。食道侧囊内皱襞较发达, 被覆复层扁平上皮, 内含较多黏液细胞, 且以Ⅳ型为主, 皱襞顶端及侧面有内含角质刺的次级突起; 黏膜下层及肌层中有固定皱襞的骨质脚根; 侧囊内胃蛋白酶活性较高。食道内皱襞较高, 被覆复层扁平上皮, 内含较多黏液细胞, 且以Ⅳ型为主。胃内皱襞发达, 被覆单层柱状上皮, 未见黏液细胞分布; 胃腺发达, 胃内蛋白酶活性较高。肠道内褶襞多, 高度呈先下降后上升趋势, 黏液细胞密度前、中肠较高, 后肠较低, 且均以Ⅰ型为主; 肠道内胰蛋白酶、脂肪酶、淀粉酶及碱性磷酸酶活性较高。幽门盲囊组织结构与肠相似。银鲳的消化道结构特点、黏液细胞分布及消化酶活性与其功能及偏肉食的杂食性相适应。     

崇安草蜥舌的显微和超微结构

采用显微技术观察了崇安草蜥(Takydromus sylvaticus)舌的显微和超微结构.舌腹面黏膜光滑;背面黏膜粗糙,由丝状乳头和轮廓乳头组成.丝状乳头锥体形,数量较多,排列成行,分布于舌体背面两侧和侧翼的腹面.在舌的横切片上有3～7个轮廓乳头,其表面平整,周围有环形沟,舌腺开口于环形沟中.舌肌肉发达.超微结构显示,舌上皮细胞问具有紧密连接,舌乳头细胞表面具有丰富的微绒毛.舌腺为单管泡状腺,分泌管由单层柱状上皮构成.柱状上皮细胞有两种,一种为分泌细胞,一种为暗细胞.分泌细胞内有典型的分泌颗粒,可协助食物的吞咽.暗细胞内无分泌颗粒,是否与离子分泌以及渗透压调节有关,尚需进一步证实.     

THE COLUMNAR CELLS OCCURRING IN THE PARIETAL LAYER OF BOWMAN'S CAPSULE : Cellular Fine Structure and Protein Transport

The renal corpuscles of adult, C3H Swiss, male mice contain testosterone-sensitive, columnar cells in the parietal layer of Bowman's capsule. A study of the normal fine structure of these cells reveals several distinctive characteristics: a microvillous brush border; apical tubular invaginations and apical tubules; an elaborate infolding of the basal surface membrane forming cellular compartments, which contain numerous mitochondria; and a complex group of membrane-limited cytoplasmic inclusions. This appearance is remarkably similar to the fine structure of cells in the proximal convoluted tubule. 1 hr after an in vivo injection of horseradish peroxidase, numerous protein-absorption droplets occur in the columnar cell cytoplasm. The speed and cytomorphology of protein transport by these capsular cells closely resemble the handling of peroxidase by the proximal convoluted tubule. Origins for these testosterone-sensitive cells are discussed briefly. Morphological evidence is presented for the differentiation of squamous cells in Bowman's parietal capsule into columnar cells, which appear structurally and functionally identical with proximal convoluted tubular epithelium.     

CELLULAR DIFFERENTIATION IN THE URINARY BLADDER OF A EURYHALINE MARINE FISH, GILLICHTHYS MIRABILIS, IN RESPONSE TO ENVIRONMENTAL SALINITY CHANGE

The urinary bladder of a euryhaline marine teleost, Gillichthys mirabilis , was studied by light and electron microscopy. An enlargement of the mesonephric ducts forms a sac-like structure lined by an epithelium composed of two major cell types. Tall columnar cells continuous with the duct epithelium are characterized by a large number of mitochondria and well-developed rough and smooth endoplasmic reticulum. Tubular smooth endoplasmic reticulum is more developed in the basal cytoplasm and often opens into the extracellular space. A second cell type, the low cuboidal cells, forming most of the bladder epithelium, has fewer mitochondria. Basal cells are rarely observed and mucous cells are absent.
In seawater Gillichthys , cells of both types are separated by narrow intercellular spaces. In 5% seawater fish, the columnar cells show functional activation, as evidenced by an increased number of mitochondria and more extensive tubular smooth endoplasmic reticulum. No such changes were noted in the cuboidal cells; however, the lateral intercellular spaces are dilated probably owing to hypotonicity of the urine in the hypotonic environment. A functional difference between the two cell types is strongly suggested. The columnar cells may be responsible for active sodium uptake in hypotonic seawater environments.     

Ultrastructure of the endolymphatic sac in the mouse.

The ultrastructure of the endolymphatic sac (ES) in the mouse was examined by light and electron microscopy. This organ was divided into three parts: proximal, intermediate and distal. In the proximal portion of the ES, the epithelium consisted of thin squamous cells. The epithelial cells had acquired basolateral processes, numerous small vesicles and well-developed Golgi apparatus. In the intermediate portion, the epithelium consisted of columnar or cuboidal cells. The epithelial cells could be classified into two types: type I and type II. The type I cells had abundant microvilli, pinocytotic vesicles, vacuoles, multivesicular bodies, lysosomes and mitochondria. The type II cells had fewer numbers of these organelles. A few free-floating cells could be observed in the lumen of this intermediate portion, most of which were macrophages. In the distal portion, the epithelium consisted of squamous or cuboidal cells. The epithelial cells had a few cytoplasmic organelles. In the ultrastructural study, each portion of the mouse ES was found to have a very distinct morphological feature. It was suggested that each of these three portions has a different function.     

The uterovaginal sperm host glands of the quail (Coturnix coturnix japonica)

Summary Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnix japonica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting of high columnar ciliated cells and small, irregular shaped, basal cells.The true glandular epithelium is composed only of columnar cells with microvilli on their luminal end. A characteristic luminal feature is a large lipid droplet in the perinuclear region. In the subplasmalemmal region numerous tubular profiles are seen which could represent a cellular resorption system.To evaluate the absorptive capacity of the Uterovaginal sperm host glands, tracer studies with HRP, ferritin, lanthanum and ruthenium red were undertaken. Since between 5 min and 3 h after injection no absorption could be found with the techniques mentioned, it is suggested that phagocytosis of spermatozoa by the glandular epithelium is not likely to occur.     

Histology,ultrastructure, and seasonal variations in the bulbourethral gland of the African straw-colored fruit bat Eidolon helvum

We studied the morphological characteristics and seasonal changes of the bulbourethral gland of Eidolon helvum in a typical African tropical environment. Forty-eight bulbourethral glands were examined using gross anatomical, histological, histochemical, and ultrastructural techniques during the early rainy, late rainy, and peak dry seasons. The pear-shaped bilateral bulbourethral glands were located extra-abdominally in the inguinal region. Trabeculae from the capsule divided the parenchyma into numerous lobules of tubuloalveolar glandular acini. The mucosa was covered by a simple columnar epithelium consisting up of principal secretory cells, columnar dense cells and basal cells, which were progressively pronounced during the dry season. The principal cells contained eosinophilic granules, which were PAS positive while the dense cells did not show affinity for the stains. The mean gross weights, acini diameters, and epithelial heights were greater during the rainy season than the dry season. Ultrastructural evaluation showed that the cytoplasm of the principal cells contained well-developed Golgi complexes, rough endoplasmic reticulum, mitochondria, and secretory vesicles of varying electron densities and sizes. The secretory vesicles were numerous during the early rainy season, decreased during the late rainy season and were scanty during the peak dry season. The simple columnar epithelium observed during the rainy season was replaced by an undefined stratified epithelium during the dry season, and this was associated with cellular degenerations and regenerations. In conclusion, E. helvum has a typical mammalian bulbourethral gland, with a unique cell type, the dense cell whose functions are not well-understood. The gland exhibits cyclical seasonal variation in structure and secretory activity; being active during the early rainy season (breeding season), and showing the lowest activity during the dry season (non-breeding season). Glandular epithelial cell renewal occurs during the dry season in preparation for the next breeding season.     

The fine structure and histochemistry of the caecal epithelium of Calicotyle kröyeri (Monogenea: Monopisthocotylea)

The caecal epithelium of Calicotyle kröyeri consists of a single cell type which functions in the uptake and intracellular digestion of host epidermis and associated mucus. Each cell is columnar with a small basal nucleus and prominent nucleolus. Perinuclear cytoplasm contains narrow profiles of GER and mitochondria with numerous cristae. Golgi complexes are small and indistinct. Most of the cell is filled with vacuoles of heterogeneous content, the largest occupying the cell apex. There is in each cell an apical endocytotic complex comprising cell surface lamellae, apical vesicles and numerous tubular invaginations of the plasmalemma. The limiting membrane of all these components is structurally modified and bears a highly organized array of peg-like structures on its luminal surface. The complex is capable of ingesting particulate food material from the gut lumen for transfer, via vesicles, to the vacuoles for digestion. Most of the vacuoles represent the digestive elements of the cell and, histochemically, are reactive for protein, mucus and carboxylic esterases. Indigestible residues and lipid droplets accumulate in the large apical vacuole and are periodically released to the lumen by exocytosis. Small, undifferentiated caecal cells were occasionally observed in the epithelium, but their development has not been recorded.     

Heterogeneous Vesicles in Mucous Epithelial Cells of Posterior Esophagus of Chinese Giant Salamander (Andrias Davidianus)

The Chinese giant salamander belongs to an old lineage of salamanders and endangered species. Many studies of breeding and disease regarding this amphibian had been implemented. However, the studies on the ultrastructure of this amphibian are rare. In this work, we provide a histological and ultra-structural investigation on posterior esophagus of Chinese giant salamander. The sections of amphibian esophagus were stained by hematoxylin & eosin (H&E). Moreover, the esophageal epithelium was observed by transmission electron microscopy (TEM). The results showed that esophageal epithelium was a single layer epithelium, which consisted of mucous cells and columnar cells. The esophageal glands were present in submucosa. The columnar cells were ciliated. According to the diverging ultrastructure of mucous vesicles, three types of mucous cells could be identified in the esophageal mucosa: i) electron-lucent vesicles mucous cell (ELV-MC); ii) electron-dense vesicles mucous cell (EDV-MC); and iii) mixed vesicles mucous cell (MV-MC).Key words: Amphibian, esophagus, ultrastructure, mucous cells, heterogeneous vesicles     

The Anatomy of the Oesophagus,Stomach and Intestine in Common Wolffish (Anarhichas lupus L.): A Basis for Diagnostic Work and Research

The alimentary canal of laboratory-reared common wolffish (Anarhichas lupus L.) was studied using light and electron microscopy. In the oesophagus, a simple columnar microvillous epithelium with transport characteristics was observed in addition to the main striated squamous epithelium. An osmoregulatory function is proposed for the simple columnar epithelium, which was supported by wide, thin-walled vessels. In the stomach, a separate type of neck cells was observed leading into the acinar gastric glands, which morphologically consist of one cell type: chief cells. The intestine was divided into a proximal and distal segment by an intestinal valve. Pyloric caeca were not present. We propose that shallow, crypt-like structures in the intestinal mucosa are the sites of epithelial-cell proliferation in juveniles and adults. The length of microvilli decreased from approximately 4 μm in the cranial part of the proximal intestine, to 1.5 μm in the distal intestine. In the distal intestine, rod-shaped bacteria were observed between microvilli. An extensive system of thin-walled vessels was observed in the submucosa of juvenile and adult wolffish stomach and intestine. Eosinophilic granular cells were numerous in the perivascular connective tissue in the gastric and intestinal submucosa of adults and juveniles, but were not observed in larvae.     

Histochemical and immunohistochemical adaptations on the gastroesophageal tube of the blue-fronted parrot (Amazona aestiva Linnaeus, 1758)

Amazona aestiva Linnaeus, 1758 is known as the blue-fronted parrot. These animals are considered seed dispersion, contributing to ecological balance. Despite its ecological importance, A. aestiva is listed as an imminent danger of becoming extinct, as it is one of the most illegally traded native species in Brazil, besides losing its habitat due to deforestation and forest fires. The cranial oesophagus mucosa is lined with a non-keratinized stratified squamous epithelium, and the basal layer presents melanocyte accumulation. No mucous glands were observed in the lamina propria/submucosa. The ingluvium two different muscular layer patterns were observed, one internal and circular and one very thick, external and longitudinal. The proventriculum submucosa consists of polygonal proventricular glands and contents into a broad central duct lined with simple columnar epithelium Periodic acid-reactive Schiff positive (PAS+) and Alcian blue positive (AB+). The 5-HT cells are dispersed in the proventricular glands located at base and apex. The ventricle mucous layer contains numerous branched folds lined by a simple columnar epithelium. The epithelium was negative reaction for PAS and positive for AB only on the fold surfaces. The 5-HT cells were scarce and observed only at the base of the ventricular gland, as well as in the adjacent connective tissue.     

臭腹腺蝗（直翅目：锥头蝗科）消化道对食物储存、消化和吸收相适应的显微结构

显微观察发现臭腹腺蝗Zonocerus variegatus（直翅目：锥头蝗科）嗉囊、中肠和后肠的肠壁结构有所不同。嗉囊为空时纵向折叠。中肠上皮层的厚度随龄期有明显变化,1龄和2龄时明显大于3龄、4龄和5龄。后肠具有帮助消化和吸收的功能。