Histochemical study on the bile duct system of normal rats

The bile duct system of normal rats was examined histochemically. Although the apical surface of biliary and glandular epithelial cells was positively stained with Concanavalia ensiformis (Con A), Dolichos biflorus (DBA), Glycine max (SBA), Ulex europeus-I (UEA-I) and Triticumvulgaris (WGA), the cytoplasm did not apparently react with any lectins. Therefore these cells might not play an important role in an active secretion of mucin. On the other hand, the cytoplasm of goblet cells was positively stained with periodic acid-Schiff, high iron diamine, Con A, DBA, Griffonia simplicifolia-II (GS-II), SBA, UEA-I, and WGA. This suggests that mucin secreted from the goblet cells may be acid one with sulfonic terminals.     

Histochemical characteristics of glycoproteins in the bile duct system of mice immunized with swine serum

The bile duct system of BALB/c and DDY mice, which were immunized with swine serum (SS) or not, was examined histochemically. Biliary epithelial cells of the SS-treated BALB/c mice, which were positively stained with periodic acid-Schiff (PAS) and had binding sites of Dolichos biflorus (DBA), were thought to secrete neutral glycoproteins with terminal N-acetyl-D-galactosamine residues. Those of the SS-treated DDY mice were however negatively or weakly stained with any histochemical stainings. On the other hand, glandular epithelial cells of the SS-treated mice of both strains, which were positively stained with high iron diamine-alcian blue (HID-AB) and had binding sites of DBA, Griffonia simplicifolia-II (GS-II), Ulex europaeus-I (UEA-I), and Triticum vulgaris (WGA), were thought to secrete glycoproteins with terminal sialic acid residues. Biliary and glandular epithelial cells of the normal mice contained only a small amount of glycoproteins showing similar histochemical characteristics to those in the SS-treated BALB/c mice. BALB/c mice immunized with SS were thought to be very useful for the investigation of production and secretion of glycoproteins in the bile duct system as well as being good model of bile duct disease.     

Histochemical characteristics of glycoproteins in the bile duct system of mice immunized with swine serum

Summary The bile duct system of BALB/c and DDY mice, which were immunized with swine serum (SS) or not, was examined histochemically. Biliary epithelial cells of the SS-treated BALB/c mice, which were positively stained with periodic acid-Schiff (PAS) and had binding sites of Dolichos biflorus (DBA), were thought to secrete neutral glycoproteins with terminal N-acetyl-d-galactosamine residues. Those of the SS-treated DDY mice were however negatively or weakly stained with any histochemical stainings. On the other hand, glandular epithelial cells of the SS-treated mice of both strains, which were positively stained with high iron diamine-alcian blue (HID-AB) and had binding sites of DBA, Griffonia simplicifolia-II (GS-II), Ulex europaeus-I (UEA-I), and Triticum vulgaris (WGA), were thought to secrete glycoproteins with terminal sialic acid residues. Biliary and glandular epithelial cells of the normal mice contained only a small amount of glycoproteins showing similar histochemical characteristics to those in the SS-treated BALB/c mice. BALB/c mice immunized with SS were thought to be very useful for the investigation of production and secretion of glycoproteins in the bile duct system as well as being good model of bile duct disease.     

Experimental study of follicle formation in suppressed parathyroid glands of Mongolian gerbils.

Parathyroid follicle formation was studied in Mongolian gerbils subjected to different concentrations of calcium in vivo and in vitro, using light and electron microscopic methods, including the potassium pyroantimonate technique and x-ray microanalysis for identification of cations. Follicles were frequent at high calcium concentration, but sparse at intermediate and low levels of calcium. Two main types of follicle were differentiated: "degenerative follicles" containing cellular debris and lined by smooth-surfaced epithelium which occasionally showed degenerative changes; and "secretory follicles" characterized by amorphous and granular contents, and an epithelium possessing microvilli and cytoplasmic projections. Amorphous masses were also seen in dilated intercellular spaces and in dilated cisterns of rough endoplasmic reticulum in the follicle epithelium. Calcium-containing precipitates were found in degenerating chief cells, and between degenerating cells and follicles. Parathyroid follicles are believed to be formed by degeneration of suppressed chief cells (degenerative follicles), and by secretion of hormonal and/or other substances into dilated intercellular spaces which progressively increase in size to form follicular cavities (secretory follicles), thereby possibly reducing the level of metabolically active parathyroid hormone. Functional suppression is believed to underlie the development of parathyroid follicles.     

Genetic consequences of group living in Mongolian gerbils

Social behavior can shape the local population genetic structure of mammals. Group living can increase pairwise genetic relatedness of mammals at a local level but differentiate the genetic structure at a population level through offspring philopatry and nonrandom mating. Our study aimed to test the hypothesis that social groups of Mongolian gerbils (Meriones unguiculatus) would consist of genetically related individuals due to offspring philopatry and would have distinct genetic structures because of restricted gene flow among social groups and nonrandom mating. We genotyped 327 wild gerbils, live captured from 28 social groups in Inner Mongolia, China, using nine microsatellite loci. The within-group pairwise genetic relatedness coefficient averaged 0.28 ± 0.14 (standard deviation), whereas the average pairwise genetic relatedness coefficient of the whole gerbil population was 0.0 ± 0.2. Additionally, the value of the global F statistic (F(st)) was 0.21, suggesting a substantial genetic differentiation among social groups of Mongolian gerbils. The Bayesian clustering divided the 327 gerbils into 23 distinct genetic clusters. Therefore, our results show that high within-group genetic relatedness and among-group genetic differentiation are the genetic consequences of group living in social mammals because of restricted gene flow, female philopatry, and nonrandom mating within social groups.     

Histochemical studies of some hepatic enzyme activities in rat during extrahepatic common bile duct obstruction.

Studies on some enzyme activities as measured histochemically in the ligated common bile duct rat liver are reported. They show principally: an increased GGT reaction in the neoductular cells; a diffusion of the LAP reaction to the neoductuli; an immediate increase and diffusion of the alkaline phosphatase reaction; an increase of G-6-PA and AMPA reactions; an increase, during the first week, of the Phyla activity and a contemporary decrease of the UDPG-GS reaction. No significant changes have been observed in other enzyme activities. By means of some dehydrogenase reactions, morphological evidence that the hepatocytes may be involved in neoductular cells formation was obtained.     

长爪沙鼠的遗传多样性分析

利用17个微卫星DNA标记对Z:ZCLA长爪沙鼠封闭群、野生群和近交系进行遗传多样性分析, 评估群体内的遗传变异和群体间的遗传分化。结果表明：在Z:ZCLA封闭群和野生群中共有9个微卫星DNA标记获得稳定的结果, 分别为AF200940、AF200941、AF200942、AF200945、AF200946、AF200947、D11Mit128、PKC和 SCN, 共检测到41个等位基因, 每个基因的等位基因数从1～7不等, 片段大小在120～283 bp之间, 所有位点的平均期望杂合度(He)和多态信息含量(PIC)值分别为0.5032和0.4656, Z:ZCLA封闭群和野生群9个微卫星位点平均有效等位基因数分别为2.78和2.89, 平均基因杂合度分别为0.3704和 0.3893, 平均多态信息含量分别为0.3256和0.3344, 两个群体都表现为中度多态, Z:ZCLA封闭群较野生群稍低; 在3个近交系中共有8个位点获得稳定的扩增结果, 分别为AF200941、AF200942、AF200945、AF200946、AF200947、D11Mit128、PKC和 SCN, 共检测到11个等位基因, 片段大小在140~241 bp之间, 其中5个位点在群体内表现为单态纯合, 3个位点在群体内表现为单态杂合, 所有位点在群体内和群体间均呈单态性, 表明这3个长爪沙鼠品系基本符合近交系的要求, 微卫星标记技术适用于近交系长爪沙鼠的遗传检测。     

Monoclonal antibodies reactive with dendritic cells of Mongolian gerbils

Mongolian gerbils (Meriones unguiculatus) serve as an valuable model animal for several infectious diseases of medical and veterinary importance. Reagents available for characterization of the immune response of Mongolian gerbils are strictly limited. We describe three novel murine monoclonal antibodies (mAbs) to dendritic cells of Mongolian gerbils. These include HUSM-M.g.11 of IgG2b isotype, HUSM-M.g. 20 of IgG2a isotype, and HUSM-M.g.30 of IgG1 isotype. All of these mAbs had an identical profile of immunohistochemical reactions with various tissues taken from immune-naive Mongolian gerbils, and were intensively expressed on dendritic cells, including epidermal Langerhans cells, B-cell follicles, and the thymic reticulum. Positive reactions of the epidermis and intestinal mucosa with these mAbs were induced by cutaneous or intestinal infections with parasites. Competitive enzyme-linked immunosorbent assay and immunoblot analysis (western blotting) indicated that all of these mAbs recognize an identical peptide epitope on a molecule with approximate molecular mass of 29 kDa. These data suggest that the mAbs recognize major histocompatibility complex class-II molecules of gerbils. Use of described mAbs would facilitate characterization of immune responses as well as investigations on host responses to infections of medical and veterinary importance, using the gerbil model.     

Colonization of Helicobacter pylori in the gastric mucosa of Mongolian gerbils

Helicobacter pylori was orally inoculated into Mongolian gerbils. The organisms were able to colonize in the gastro-mucosal layer of the gerbils, especially in those gerbils which had mucosal lesions caused by indomethacin treatment. The pathological changes developed by H. pylori infection were restricted to the stomachs, and only slightly inflammatory cells were observed.     

限食及重喂食对雄性长爪沙鼠生理指标的影响

限食通常会显著影响鼠类的营养及内分泌等生理指标,但限食后重喂食其生理指标是否能得以恢复尚不
清楚。本文采取70% 的限食水平,研究了限食及重喂食对雄性长爪沙鼠生理指标的影响。将雄性长爪沙鼠分为
限食组、重喂食组和对照组。限食组先自由饮食4 周,后70% 限食4 周;重喂食组先70% 限食4 周,后恢复自
由饮食4 周。对照组自由饮食8 周。实验结束时,检测各组肥满度及血清白蛋白和总蛋白含量、血清甲状腺素
T3 和T4 水平、睾酮和皮质醇含量等各项生理指标的变化。研究结果表明,4 周限食显著降低了雄性长爪沙鼠的肥满度和血清甲状腺素T4 含量,显著升高了其血液皮质醇含量;限食后重喂食4 周后可使上述指标恢复或接近正常,但血清白蛋白含量比对照组低,其他指标与对照组无明显差异,长爪沙鼠的一些生理指标在限食重喂食
后能得以恢复,但其内分泌调节可能存在新的变化,值得进一步研究。     

Propagation of nephropathia epidemica virus in Mongolian gerbils.

Nephropathia epidemica virus, the etiological agent of hemorrhagic fever with renal syndrome in Scandinavia, was serially propagated in Mongolian gerbils (Meriones unguiculatus). Intracerebrally inoculated suckling gerbils developed subclinical infections, with viral antigen found in lung, brain, liver and spleen. The distribution of viral antigen was similar to that seen in experimentally infected bank voles (Clethrionomys glareolus), the principal wild rodent reservoir of nephropathia epidemica virus. This model provides a readily available animal host for the study of experimental nephropathia epidemica virus infection.     

Histological observation on the female prostate in Mongolian gerbils (Meriones unguiculatus).

In Mongolian gerbils, prostatic buds were found in female fetuses at the 23rd day of gestation. In the mothers the well-developed prostate gland consisting of a paired lobes was situated on either side of the neck of the bladder.     

The effect of food deprivation on drinking and running in Mongolian gerbils

Three experiments are reported in which adult male Mongolian gerbils (Meriones unguiculatus) were subjected to various degrees of partial food deprivation, with or without simultaneous access to a running wheel. Experiment 1 showed that restricted feeding caused drinking to increase and running to decrease, and it offered no support for the idea that running might substitute for drinking. Experiment 2 showed that running declined, and then at least partly recovered, as a function of body weight loss, in gerbils that were not allowed to become hyperdipsic. Experiment 3 showed that drinking remained at a high level during prolonged exposure to restricted feeding, but reverted to baseline level more rapidly than did body weight when free feeding was reinstated. The results do not support the idea that drinking and running are interchangeable members of a set of activities facilitated by food deprivation, and they show that neither drinking nor running is related to degree of body weight loss in a simple manner.     

Effects of supplemental food on the social organization of Mongolian gerbils during the breeding season

Social groups occur in many rodents and vary in size and complexity under varying environments. Food availability is often limited in northern temperate regions and alters the life history and behavior of rodents. Increased food availability is hypothesized to increase the size and complexity of rodent social groups by enhancing individual survival and philopatry. We tested this hypothesis in Mongolian gerbils Meriones unguiculatus under semi-natural conditions in Inner Mongolia, China. The Mongolian gerbil is a cooperative breeder living in groups year-round. Gerbil colonies in 10 m × 10 m chambers were the experimental units, with four replicate chambers each for food supplementation and food unsupplemented controls in 2004 and six replicate chambers for each treatment in 2005. At 2-day intervals wheat grain supplemented the normal food in experimental chambers throughout the breeding season (May through August). We estimated founder mortality, cumulative recruitment, proportion of philopatric juveniles, ages at sexual maturity and social group size in each colony from May through August. Rates of change in group size were inversely related to social group size. The social organization of Mongolian gerbils did not differ in any of the measured parameters between food-supplemented and -unsupplemented chambers. Therefore, additional food does not influence the social organization of Mongolian gerbils during the breeding season.     

Effects of antioxidant vitamin supplements on Helicobacter pylori-induced gastritis in Mongolian gerbils

BACKGROUND: Epidemiological studies show that high intake of food-bound vitamin C and E reduces the risk of gastric cancer. Whether dietary supplementation with antioxidant micronutrients interferes with Helicobacter pylori infection and associated diseases is unclear. The aim of this study was to investigate if dietary vitamin C or E supplementation influences the progression of gastritis, gastric mucosal nitrosative and oxidative protein damage, gastric mucosal lipid peroxidation, or gastric mucosal oxidative DNA damage in H. pylori-infected Mongolian gerbils. MATERIALS AND METHODS: Gerbils were divided into four groups: H. pylori-infected animals fed with vitamin C- or vitamin E-supplemented food, and infected and uninfected animals given standard rodent food. Subgroups of animals were killed at different time-points until 52 weeks postinfection. Concentrations of 3-nitrotyrosine and thiobarbituric acid-reactive substances (TBARS) in the gastric mucosa were determined with an immunodot blot and a fluorometric method, respectively. Mucosal concentrations of carbonyl carbons on proteins and 8-hydroxydeoxyguanosine were determined by enzyme-linked immunosorbent assay. Gastritis was scored semiquantitatively. RESULTS: Vitamin supplements had no effect on the colonization with H. pylori. Vitamin C as well as vitamin E supplements reduced mucosal 3-nitrotyrosine concentrations to normal levels in infected animals. Vitamin E supplements decreased mucosal protein carbonyls and TBARS in short-term gastritis. In addition, vitamin C supplements caused attenuated mucosal oxidative DNA damage and milder mucosal inflammation in short-term gastritis. CONCLUSION: Vitamin C or vitamin E supplementation leads to some short-term protective effects on H. pylori-induced gastritis in Mongolian gerbils. These effects seem to subside over time when the infection persists.     

Development of the endocrine cells in the rat pancreatic and bile duct system

Summary Morphological features of the endocrine cells in the duct system of the pancreas and the biliary tract have been recently characterized in the adult animal with respect to their physiological roles. In the present study, we have investigated their chronological appearance as well as their developmental progress at various stages of the rat fetal and postnatal life. On day 12 of gestation, glucagon and insulin, as well as CCK cells, were identified in the pancreatic primordium. On day 14, glucagon and CCK cells were first detected in the epithelial lining of the common hepatic and the hepatic ducts. These cells remained the dominant endocrine type in the duct system during the fetal period. Insulin and pancreatic polypeptide cells were first observed in the common hepatic duct only on days 16 and 18 of gestation respectively. In spite of their presence in the islets, somatostatin cells were not detected in the duct system during fetal life. They started to appear in the accessory pancreatic duct of the neonate, and subsequently in the common hepatic duct as well as in the small pancreatic ones on day 7 after birth. During postnatal development, the endocrine cells showed progressive or retrogressive changes in different portions of the duct system according to the cell type. In general, somatostatin, CCK and pancreatic polypeptide cells showed an increase, while glucagon and insulin cells gradually dwindled in number up to the adult stage. Somatostatin cells exhibited a significant increase in number, becoming the highest population among the duct endocrine cells in the adult. Throughout the developmental progress, the endocrine cells appear to be allocated in regions relevant to their possible influence modulating the exocrine secretion as well as the drainage of the pancreatic and bile fluid. To whom correspondence should be address.     

A study of the conversion of cholesterol to bile acids by the use of a fistulated bile duct

A method for the surgical preparation of a bile fistula in the sculpin Myoxocephalus quadricornis is presented. This model was used in demonstrating the conversion of ¹⁴C-cholesterol into bile acids. The main acid metabolite was cholic acid and the presence of dihydroxy bile acids was also demonstrated. The amount of labelled compounds which was recovered in the bile was small both in case of parenteral administration to fistulated sculpins and after peroral administration to intact animals. This may be attributable to slow metabolism at the low ambient temperature these animals require to survive.