胸导管结扎对大鼠脂质代谢和胰组织结构的影响

目的:探讨胸导管结扎对脂质代谢的影响,揭示淋巴回流障碍诱发胰组织的显微和超微结构变化.方法:SD大鼠随机分为假手术对照组和结扎胸导管模型组.术后6个月取静脉血标本进行血脂检测;部分胰组织标本,H-E和刚果红染色光镜观察;部分胰组织进行透射电镜观察.结果:(1)模型组大鼠游离脂肪酸和甘油三酯浓度明显下降,胆固醇浓度无显著变化.(2)光镜观察显示模型组大鼠的胰腺小叶间隙增宽,脂肪堆积和淋巴管扩张.(3)透射电镜观察显示模型组大鼠的胰岛细胞间隙增宽,细胞间隙及细胞内可见大量脂滴样物质、红细胞和胶原原纤维样结构.结论:胸导管结扎可引起胰腺结构变化和影响胰腺的内、外分泌功能.     

小鼠胰腺淋巴管的分布及其与胰岛的关系

目的:探讨小鼠胰腺淋巴管的形态分布及其结构特点。方法:对小鼠胰组织切片进行HE染色,5核苷酸酶(5-Nase)和碱性磷酸酶(ALP)双重染色,光镜、透射电镜、扫描电镜二次电子和背散射电子图像(SEI/BEI)观察。结果:小鼠胰腺的淋巴管结构较典型,在胰腺的小叶间结缔组织内,较大淋巴管与血管和导管相互伴行;毛细淋巴管起自胰腺腺泡周围,并且均匀地分布于整个小叶内;小叶内有单独走行的集合淋巴管,亦存在与血管并行情况;在胰岛内部未发现毛细淋巴管,但胰岛周围可见丰富的毛细淋巴管。结论:小鼠胰腺小叶间和小叶内结缔组织中,均有淋巴管分布;胰岛内部虽无淋巴管,但胰岛与周围毛细淋巴管的关系较密切。     

胰淋巴管的微细分布

为探讨胰小叶内是否存在淋巴管，用５′－核苷酸酶－碱性磷酸酶双重染色，半薄、超薄切片，光镜和电镜下观察了兔胰淋巴管的微细分布。结果表明，胰的淋巴管仅见于胰小叶间的结缔组织内。在胰小叶内，包括胰岛内均无淋巴管，只见到丰富的血管     

大鼠胰淋巴管的微细分布

采用半薄切片光镜观察和超薄切片电镜观察方法研究了大鼠胰淋巴管的微细分布。结果证明 ,在胰小叶内包括胰岛内及其周围均不存在毛细淋巴管和淋巴管而有丰富的血管 ;胰的毛细淋巴管和淋巴管仅见于小叶间的结缔组织内。     

胰组织结构提示多肽胰岛素的正常转运经淋巴而非门脉途径

目的　探讨胰岛多肽激素释放形式和细胞外正常转运途径的结构基础。方法　对大鼠和人胰尾部组织进行了光镜 (LM )和透射电镜 (TEM)观察。结果　胰组织主要由腺泡构成的腺小叶和分隔腺小叶的结缔组织所组成。胰腺的导管、血管和淋巴管 ,有髓和无髓神经纤维 ,均穿行于胰结缔组织内。在胰岛周围的结缔组织间隙内也可见到完整的膜包分泌颗粒 (2 0 0～ 5 0 0nm)。胰腺的毛细血管为窗孔 (5 0nm)型。结论　胰组织结构特点提示 :胰岛多肽激素的释放形式 ,可能是连同颗粒膜的整体释放而非传统认为的胞吐分泌 ;释放入胰组织液中的多态胰岛素或分泌颗粒 ,更易进入淋巴而非门脉血液     

胰器官内淋巴管的研究

应用光镜和电镜的观察方法研究了新生儿尸体的胰器官肉淋巴管的微细分布及超微结构。结果是在胰小叶间结缔组织内存在有丰富的毛细淋巴管及淋巴管，在胰被膜内有较多的淋巴管。而胰小叶内，胰岛内部及其周围均未见到毛淋巴管，仅有丰富的毛细血管，胰的毛细淋巴管具有其他器官毛细淋巴管超微结构的特点。     

大鼠增龄中胰腺超微结构的变化及胰岛的分布规律

目的探讨胰腺超微结构的增龄变化及胰岛的分布规律,以提供胰腺移植的参考。方法取30只健康sD大鼠,分3组,幼年、青年、老年各10只,每只取胰头、体、尾做组织切片光镜观察。每组选3只取胰尾做透射电镜观察。结果透射电镜观察老年鼠胰腺外分泌部的腺细胞,胞核固缩,酶原颗粒减少,线粒体脱嵴肿胀,粗面内质网扩张,出现脂滴,溶酶体增多,而内分泌部的B细胞分泌颗粒空晕增宽,数量减少,粗面内质网脱粒,线粒体减少。A细胞无明显年龄变化。光镜观察老年鼠胰腺小叶间结缔组织增生,胰岛的分布以幼鼠胰尾数量为多。结论胰腺外分泌部的腺细胞和内分泌部的B细胞呈现与年龄相关的结构变化,胰岛的分布以幼鼠胰尾的胰岛数目为最多。提示胰腺移植的供体以幼年胰尾为佳,老年不宜。     

高脂饮食诱发肥胖大鼠胰腺结构变化及其与糖尿病的关系

目的：观察高脂饮食诱发肥胖大鼠胰腺的结构变化,并探讨其与糖尿病的关系。方法：选用出生21 d雄性SD大鼠,经高脂饲料喂养,衡量其肥胖程度,检测血糖、胰岛素和C-肽水平,光镜和透射电镜观察胰组织等变化。结果：经高脂饮食诱发的肥胖大鼠,血糖、胰岛素光子数均高于对照组,血C-肽光子数与对照组差别不显著;肥胖大鼠的胰腺腺泡间或小叶间,出现脂肪细胞堆积,淋巴细胞浸润和结缔组织纤维增生;某些腺泡和胰岛细胞出现脂肪或空泡样变性。结论：高脂饮食可诱发大鼠肥胖,并出现血糖、胰岛素水平和胰组织结构的变化;该变化可能与胰组织通道阻塞、胰淋巴回流障碍、胰岛素等多肽激素转运异常有关。     

一种用5'-Nase-ALPase染色观察大鼠胰腺组织的方法

目的 观察大鼠胰腺组织血管淋巴管分布特点.方法 通过5’一核苷酸酶和碱性磷酸酶组织化学双重染色相对比,光镜观察大鼠胰腺组织脉管结构.结果 光镜显示,血管显示碱性磷酸酶强阳性蓝色反应,淋巴管呈现5'-核苷酸酶强阳性褐色反应.在腺泡之间和胰岛内部,存在丰富的毛细血管;毛细淋巴管只见于胰岛的周围.结论 胰岛的淋巴引流,可能是通过淋巴管前通路实现的.     

人胰结缔组织纤维的细微和超微构筑及其意义--NaOH消蚀法SEM观察

目的探讨胰结缔组织纤维的细微和超微构筑及其意义.方法采用NaOH消蚀和超声波(USW)清洗技术,制备只保留结缔组织纤维成分的人胰组织样品,进行扫描电镜(SEM)观察和分析.结果经NaOH消蚀和USW清洗处理的胰组织,其细胞和基质成分全被消蚀掉,只留有结缔组织纤维,仍保持原有构筑特征.胰腺小叶、小叶间结缔组织和胰岛的轮廓清晰可见.穿行于小叶间结缔组织内的胰腺导管、动脉和静脉血管、淋巴管以及神经纤维束,易被辨认和区别.结缔组织纤维织成的束或网,均由胶原蛋白聚合而成的纳米(10-100mm)纤维,或称胶原细纤维所组成.结论活体上充满组织液的胰结缔组织纤维网,构成了该器官的组织支架和通道,为胰内、外分泌细胞的支持与保护、营养与代谢、分泌与通讯、再生与修复等,提供了适宜的微环境.     

大鼠胰组织块的三维重建及形态学测量

目的:观察大鼠胰组织块内部各结构的空间位置关系,并描述胰岛的立体形态学特征.方法:经过长序列连续切片、H-E染色、切片图像数字化及配准等步骤,建立正常大鼠胰组织块的数字化图像数据集,对其内部的动脉、静脉、导管及胰岛进行分割及三维重建,并对重建结果进行测量及分析.结果:所得数字化图像数据集分辨率高,配准准确,再现了原组织的结构,重建结果可在三维空间内自由观察.根据重建结果测量多种形态学指标.胰腺泡及结缔组织占胰总体积的绝大部分,胰岛占1.125%.结论:胰内动脉、静脉分支自主干垂直发出后,互相伴行,先于胰表面,随后向小叶深部发出分支.胰导管走行独立,分支间存在吻合.某些部位动脉、静脉与导管并行,形成三联管结构.胰岛与导管系统关系密切.     

Amyloidosis of pancreatic islets in primary amyloidosis (AL type)

Seven cases of primary amyloidosis (AL-type) were studied immunocytochemically for the possible involvement of pancreatic islets. The two cases with extensive organ involvement by AL-amyloidosis revealed amyloid deposits in pancreatic islets by routine HE and Congo red staining, which were positive for amyloid p and amyloid a, but were only focally positive for light chains kappa and lambda. Positive staining for amyloid p and amyloid a was also noted in the scattered pancreatic acinar tissues, and this positive staining was not specifically located in pancreatic islets as seen in type 2 diabetes mellitus. It is concluded that amyloid deposits in pancreatic islets occur in systemic AL-amyloidosis by a different mechanism from type 2 diabetes. Islet amyloidosis in AL-amyloidosis appears to deposit via circulation, depositing in both pancreatic islets and acinar tissue through blood vessels. In type 2 diabetes, beta islet cells die by cytotoxic effects of smaller amylin (islet amyloid polypeptide, IAPP) aggregates, and the interstitial space created by the necrotic beta cells is replaced by larger IAPP aggregates, to form complex, polymerized islet amyloid. In AL-amyloidosis, the amount of amyloid and light chain deposits in pancreatic islets is much less than that of the other organs and appears to have no connection to type 2 diabetes because the patients did not present diabetes or hyperglycemia. However, considerable islet amyloidosis can be seen in severe AL-type amyloidosis.     

人胚胎期胰腺的形态学研究

本研究收集胎龄5～41周的人胚胎53例,取胰腺,Bouin液固定,按常规制石蜡切片。部分切片经阿利新蓝-焰红、硝酸银-醛复红-铅苏木精等方法染色,部分切片作免疫组织化学PAP反应,观察胰岛A、B和D细胞。取不同胎龄的胰尾组织14例,戊二醛固定,Epon812包埋,透射电镜观察。本文的结果表明,胰腺内分泌部主要是由胰管2级以下分支的管壁上皮细胞,向周围的间充质内增生和分化而成。胎龄12周时,即可在光镜下辨认A、B及D细胞;电镜下观察,胰腺外分泌细胞在胎龄14周以后,才能见到分泌颗粒,证明胰岛细胞的分化早于外分泌细胞。测量16～36周胎儿胰腺内胰岛所占的比例,证明胚胎期胰腺内分泌部所占比例远高于成年人。本实验为临床使用人胎胰岛移植提供了参考资料。     

An alternative method for preparation of tissue sections from the rat mammary gland

In toxicopathological studies of the rat mammary glands, the guidelines of the Registry of Industrial Toxicology and Animal Data (RITA) recommend transverse sections of the inguinal mammary gland. However, occasionally limited amounts of mammary gland tissue are found in transverse sections. We compared transverse sectioning with an alternative method comprising horizontal sections of the rat mammary glands. Normal cycling female Sprague Dawley rats were sacrificed in proestrous, estrous, metestrous and diestrous, and samples from all mammary glands were collected. Transverse sections were prepared from the left-sided glands, and horizontal sections were cut from the right-sided glands. Sections were stained with HE, and epithelial and myoepithelial cells were visualized by immunohistochemical staining of cytokeratin 18 and alpha smooth muscle actin, respectively. Area of the mammary fat pad, mammary epithelium and connective tissue were measured in randomly sampled vision fields from each section. Horizontal sections contained a significantly larger area of mammary fat pad as well as glandular and connective tissue. No differences in tissue densities of epithelial or myoepithelial cells or connective tissue were observed between transverse sections and horizontal sections. Interestingly, densities of epithelium and connective tissue varied between cranial and caudal glands as well as the phases of the estrous cycle. In conclusion, horizontal histological sections of the rat mammary gland provided significantly larger samples of mammary gland tissue with no difference in tissue composition compared to transverse sections, which are recommended in the RITA guidelines.     

Release of insulin in vitro from normal and duct-ligated rat pancreas.

Ligation of the pancreatic duct causes atrophy of the acinar cells but leaves the endocrine tissue intact. In the present study, a partial ligation of the pancreatic duct was performed in the rat, and the in vitro insulin response to glucose was compared from both the atrophic and non-atrophic portions of the pancreas. Subsequent morphological studies of the duct-tied portion of the pancreas indicated a complete lack of acinar cells and a possible neoformation of ducts, fat cells and connective tissue. However, islets were present in normal amounts and appeared well perserved. Measurements of the insulin release in vitro from this ligated pancreatic tissue showed that an increase of the glucose concentrations from 3.3 to 16.7 mmol/1 resulted in a six-fold stimulation. A further two-fold stimulation was seen after addition of theophylline to the high-glucose incubation medium. In addition, only under the latter conditions was there a significantly increased insulin release from both non-atrophic portion of the pancreas and from the pancreas of sham-operated animals. It is concluded that duct ligation does not diminish the glucose sensitivty of rat islet B-cells. Thus, the present study does not support the view proposed previously that islet tissue is functionally of a foetal nature following duct ligation.     

Origins and pathways of fluid entering sublobular lymphatic vessels in cat livers

The liver, which produces a large volume of lymph, has a lymphatic system which can be classified into three categories: portal, sublobular, and superficial lymphatic vessels. As little is known about the origin and pathways of sublobular lymph, this study demonstrates pathways of interstitial fluid flowing into sublobular lymphatic vessels. Livers from cats whose thoracic ducts were either ligated or non-ligated were examined by light-, transmission electron- and scanning electron-microscopy (SEM). Complete ligation of the thoracic duct caused significant dilation of the hepatic sinusoids, the space of Disse, and channels passing through the limiting plate. Sublobular interstitial space and sublobular lymphatic vessels were also expanded. The channels between hepatocytes forming the limiting plate contained collagen fibers, and connected the space of Disse with a sublobular interstitial space. The alkali-water maceration/SEM confirmed that collagen fibers traversing the layer of the limiting plate independently of blood vessels connected collagen fibers in the space of Disse with those in the sublobular space. Complete ligation of the thoracic duct also showed an accumulation of mast cells and plasma cells in the sublobular interstitial space. Our data suggest that fluid in the space of Disse flows along collagen fibers in channels traversing the limiting plate as well as those along the sinusoids and central veins that drain into sublobular veins, and enters the sublobular interstitial space to finally lead into sublobular lymphatic vessels. Our study has also shown that hepatic lymphostasis causes the accumulation of mast cells and plasma cells in the sublobular interstitial space, which may be involved in lymphangiogenesis and fibrogenesis.