Comparative studies on distribution and fine morphology of the intestinal Peyer's patches in Mongolian gerbils (Meriones unguiculatus) and mice.

The intestinal Peyer's patches (PP) were significantly different in distribution and fine morphology between Mongolian gerbils and mice. The PP of gerbils were evenly distributed from the duodenum to ileum, whereas the PP of mice were more densely distributed in the lower ileum than other parts of the intestine. In gerbils, each PP had a much greater number of lymphoid follicles than in mice, although the total number of PP was smaller. Electron microscopy revealed that the PP dome of gerbils was covered with two types of epithelial cells, one with shorter microvilli and the other with longer ones, whereas the epithelial cells of the murine PP dome was uniform-shaped with numerous medium-sized microvilli. Some dome absorptive cells of gerbils were morphologically similar to poorly differentiated crypt cells of mice, suggesting to be immature M cells.     

Enteric cryptosporidial infection in pigs: 184 cases (1981-1985)

Cryptosporidia organisms were detected histologically in the microvillus brush border of 5.3% (184/3,491) of consecutive live pigs submitted for routine diagnostic evaluation between 1981 and 1985. Infected pigs came from 133 farms and usually were 6 to 12 weeks old, but ranged from 1 to 30 weeks old. Organisms were found in the jejunum, ileum, cecum, and colon, but primarily in microvilli of dome epithelium in the ileum. A seasonal incidence was not observed. Only 26% of the cryptosporidia-infected pigs had diarrhea, and most of those had other primary diarrheagenic agents or lesions capable of causing their diarrhea.     

Morphometric analysis of the activity of alkaline phosphatase in the small intestine of piglets infected with the coccidium Isospora suis

Gnotobiotical one-day-old piglets were infected with 100,000 Isospora suis coccidia oocysts, and were immediately killed. In piglets killed on the 3rd to 11th day after infection (DAI), the morphometric analysis of alkaline phosphatase activity was performed in the area of the microvillus zone of small intestine. In the control 2-7 days old animals, the small intestine was not equally supplied with alkaline phosphatase. In duodenum the activity reached 88.37 per cent of the active length of absorbent surface (% LAac), in the middle jejunum 95.98 per cent LAac, in the dorsal jejunum 78.63% LAac and the ileum 90.55 % LAac. The width of the active area was more balanced and ranged from 5.003 microM in the ileum to 6.129 microM in the dorsal jejunum. In infected gnotobiotical piglets the lowest activity was found out on the 3rd to 4th DAI, with a greater decline on the 9th day after infection. The range from 25.99 to 40.50 per cent LAac with minimum in the duodenum and maximum in the ileum was observed on the 3rd DAI. In the middle and dorsal ileum the activity was nearly equal (28.34 and 27.69 per cent LAac). nI the dorsal jejunum a moderate increasing was up to 47.13% LAac on the 4th DAI, with the exception of the ileum, where the activity of alkaline phosphatase decreased to 24.96% LAac. On the 9th DAI the activity of alkaline phosphatase was nearly equal in the whole small intestine (from 55.70 to 60.01% LAac) with the maximum in the middle jejunum. In the width of the reaction product a direct dependence on the total activity of alkaline phosphatase was evident only in the segment of the middle and dorsal jejunum and ileum, but merely on the period of the 3rd to 4th DAI. The lowest values were measured in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI). No dependence was observed between the total activity and the reaction product in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI), there was no general stabilisation of the activity of alkaline phosphatase.     

Effect of rotavirus and/or Escherichia coli infection on the aggregated lymphoid follicles in the small intestine of neonatal gnotobiotic calves

The effect of rotavirus and/or Escherichia coli infections on the follicle-associated epithelium (FAE or M cells) of the domes of the aggregated lymphoid follicles (ALF, or Peyer's patches) of gnotobiotic calves was evaluated by light, scanning electron, transmission electron, and immunofluorescence microscopies. Calf rotavirus (CRV) infection produced loss of FAE cell microvilli, and virions were observed in cytoplasmic vacuoles of FAE cells, as well as in intercellular spaces between FAE cells and lymphoid cells migrating through the dome epithelium. The CRV particles appeared to have entered the FAE cells by phagocytosis, with no subsequent cytoplasmic replication. Enterotoxigenic E coli (ETEC) induced more severe alterations including marked microvilli loss and ballooning in the FAE cells. There was no adhesion to, or colonization of FAE cells by ETEC, but bacteria were observed free or phagocytized within the dome and the germinal centers of the ALF. There were no ETEC observed in the cytoplasm of FAE cells. The presence of nonenterotoxigenic E coli (NETEC) in the intestine of calves had no effect on the intestinal FAE cells. The addition of NETEC to CRV infections did not enhance or modify in any way the response of FAE cells to the viral infection; however, the combination of CRV + ETEC produced severe necrosis of the FAE cells, and loss of dome epithelium of ALF.     

Disaccharidase activity in intestine epithelium microvilli membranes of lambs during the first month after birth

Disaccharidase activity was studied in microvilli membranes of enterocytes isolated from duodenum, jejunum and ileum of lambs at an age of 1, 7 and 23 days. A maximum of lactase activity was observed on the 7th day compared to activity on 1st and 23rd day after parturition and a decrease in enzyme activity on the 23rd day compared to activity on the 7th day. Differences, however, were significant only in respect to activity in ileum. A significant increase of maltase activity in ileum and jejunum was established on the 7th and 23rd day compared to activity on the 1st day after parturition. Trehalase activity attained a maximum in all the three intestine divisions, consequently it subsided with no statistically significant differences. Lactase activity in ileum was significantly lower compared to activity in jejunum of lambs at an age of 1 and 23 days. A marked decrease of maltase activity in distal direction was found only on 1 day-old lambs. No significant alterations were observed in trehalase activity along the small intestine of lambs of the three age groups.     

Localization and activities of lysosomal enzymes in jejunal and ileal epithelial cells of the young pig

The localization and the specific activities of lysosomal enzymes in jejunal and ileal epithelium of suckling pigs were determined. Acid phosphatase was found in pinocytotic vesicles and vacoles at both intestinal sites in pigs examined during (less than or equal to 1 day old) or shortly after (2 days old) closure. These pinocytolically active vesicles and vacuoles were determined to be phagolysosomes. In the ileum, phagolysosomes persisted well after closure, at an age (10 days) when ileal epithelium retains the capacity for pinocytotic uptake of immunoglobulin, but does not transport it to blood. Neither jejunum nor ileum contained phagolysosomes at an age (30 days) when the intestine had lost both uptake and transport capacities. The specific activities of acid phosphatase and cathepsin B-1 in jejunum were similar for all age groups. However, the activities of these enzymes in ileum of 10-day-old pigs were three and five times greater than at any other age or site. The results are consistent with phagolysosomes in the ileum of 10-day-old pigs functioning as a "barrier" which prevents transport of the macromolecules which are taken up pinocytotically by this epithelium. The results do not permit conclusions whether (or not) the phagolysosomes which appear in jejunum and ileum of pigs less than or equal to 1 day old contribute to closure, because the transcellular route for immunoglobulin absorption in pigs has not been precisely defined.     

A scanning and transmission electron microscopic study of rotavirus-induced intestinal lesions in neonatal gnotobiotic dogs

Neonatal gnotobiotic dogs orally inoculated with canine rotavirus had ultrastructural changes limited to the jejunal and ileal regions of the small intestine. Early scanning electron microscopic findings consisted of swollen villus epithelial cells, denuded foci on intestinal villi, and slight to moderate villus atrophy. Later changes were slight villus atrophy with no denuded intestinal villi. Transmission electron microscopic changes in villus epithelial cells from 12 to 48 hours post-inoculation included: rotavirus particles associated with intracytoplasmic vacuoles near the terminal web and apical tubules; viral particles in dilated cisternae of rough endoplasmic reticulum; and moderate numbers of necrotic cells having no microvilli, swollen mitochondria, membrane-bound lipid-like material in the cytoplasm, clumped chromatin around the periphery of the nucleus, and disruption of the cytoplasmic membrane. In jejunum and ileum at 72 to 154 hours post-inoculation, there were fewer necrotic villus epithelial cells and fewer virus particles. In addition, the ultrastructural morphology of the majority of the villus epithelial cells was similar to crypt epithelium. These studies showed that rotavirus infected the villus epithelial cells with subsequent propagation of the rotavirus and destruction of villus epithelial cells.     

Pathogenesis of intestinal cryptosporidiosis in conventional and gnotobiotic piglets.

The pathogenesis of intestinal cryptosporidiosis was studied in 52 conventionally reared and 20 gnotobiotically reared piglets by inoculation with different doses of Cryptosporidium parvum oocysts. The prepatent period of C. parvum in both groups of animals were variable, depending on the number of oocysts administered. The patent period of C. parvum in conventionally reared piglets was 8 or 9 days; in gnotobiotic piglets cryptosporidia were found in feces until Day post infection (DPI) 16, when the last piglet was necropsied. Cryptosporidiosis in conventionally reared piglets is a self-limited diarrheal disease associated with morphological changes within the intestine. The most severe lesion was seen in the posterior jejunum and ileum from DPI 3 to DPI 7, and consisted of villous atrophy, crypt hyperplasia and inflammatory infiltration in the lamina propria. In gnotobiotic piglets cryptosporidia induced severe enterocolitis which occurred at least until DPI 16. The characteristics of enteric lesions were similar to those found in conventionally reared piglets. Intestinal cryptosporidiosis in both groups of animals shifted in the course of infection in the caudal direction and terminated in the large intestine. Examination by scanning electron microscope showed that infected absorptive cells had thicker and longer microvilli than those on non-infected cells; neighboring non-infected cells were hypertrophic, bulbously protuberant with minute microvilli with no distinct intercellular borders. Numerous cryptosporidia in the heterotopic glandular epithelium in the submucosa of cecum and colon on DPI 9 and 10 were found. No differences in the location and degree of cryptosporidial infection between colostrum-fed and colostrum-deprived conventionally reared piglets were found. Sow's colostrum does not appear to protect piglets from C. parvum infection. The role of intestinal microflora in the pathogenesis of cryptosporidiosis in piglets is discussed.     

The small intestine of the adult New Hampshire chicken: an immunohistochemical study

The presence and distribution of glucose-dependent insulinotropic polypeptide or gastric inhibitory polypeptide (GIP), gastric-releasing peptide (GRP) and glucagon immunoreactivity were studied in the small intestine of the New Hampshire chicken using immunohistochemistry. This is the first report of the presence of GIP-immunoreactive (ir) cells in avian small intestine. GIP, GRP and glucagon immunoreactivity was localized in the epithelium of the villi and crypts of the duodenum, jejunum and ileum. In particular, both in the duodenum and in the jejunum immunoreactive endocrine cells to GIP, GRP and glucagon were observed. In the ileum, we noticed GIP-ir and glucagon-ir cells. GRP-ir was found in nerve fibres of all three segments of the small intestine. The distribution of these bioactive agents in the intestinal tract of the chicken suggests that GIP and glucagon may play a role in the enteropancreatic axis in which intestinal peptides modulate pancreas secretion.     

Über die pränatale Entwicklung der Lamina epithelialis in der Phase der Vakuolisierung villärer Epithelzellen. Untersuchungen am Darm des Rindes (Bos primigenius taurus L., 1758)

The development of the bovine small intestine was examined in 39 embryos and fetuses by light microscopic and transmission electron microscopic methods. Special reference was paid to the histogenesis of the ephithelium. In contrast to the duodenum the epithelium of jejunum and ileum undergoes a degeneration by vacuolation of its villous epithelial cells. The demonstration of the acid phosphatase activity of these vacuoles shows their lysosomal character. This degenerative process of the small intestinal epithelium is also known in large intestine where it leads to the destruction of the intestinal villi. Both seem to be part of a ‘principle of construction of the intestine of the vertebrates’(Wille, 1984).     

羔羊小肠pH及主要消化酶发育规律的研究

对小尾寒羊羔羊小肠不同部位(十二指肠、空肠和回肠)pH及淀粉酶、胰蛋白酶、糜蛋白酶、脂肪酶和乳糖酶的活性进行了测定，结果表明：羔羊小肠不同部位内容物pH不同，回肠pH显著高于空肠，空肠和回肠pH显著高于十二指肠，羔羊1月龄后，小肠各段pH变化不大；小肠不同部位淀粉酶和胰蛋白酶、糜蛋白酶及脂肪酶活性不同，空肠段淀粉酶、胰蛋白酶、糜蛋白酶及脂肪酶活性高于十二指肠和回肠段，随着羔羊日龄的增长，小肠淀粉酶、胰蛋白酶、糜蛋白酶及脂肪酶活性增加，3月龄后各消化酶活性变化差异不显著(P＜O．05)；羔羊小肠不同部位乳糖酶活性不同，空肠乳糖酶活性显著高于十二指肠和回肠，随着羔羊日龄的增长，小肠乳糖酶活性逐渐降低。     

贝氏莫尼茨绦虫感染绵羊对小肠局部黏膜淋巴组织的影响

为了研究贝氏莫尼茨绦虫自然感染绵羊对小肠黏膜免疫组织的影响,分别从宏观、微观及亚微观水平对自然感染贝氏莫尼茨绦虫的成年绵羊(感染组)肠道进行了细致地观察,并与正常成年绵羊(正常组)进行了比较.结果显示,感染组肠道所见虫体平均长度为1.5m,头节主要吸附在空肠淋巴集结分布丰富的部位,一般寄生数量为1～2条.眼观,虫体寄生部位黏膜增厚,表面有大量灰白色黏液附着,其间可见点状出血.镜下,局部黏膜上皮脱落,而在完整的黏膜上皮处,其上皮细胞、上皮内淋巴细胞、杯状细胞的数量都明显增多;固有层内毛细血管充血,淋巴细胞、浆细胞、弥散淋巴组织以及肠腺杯状细胞均有不同程度的增生,头节寄生处部分肠腺坏死;黏膜下层淋巴小结、淋巴集结显著增生,部分增生凸入固有层形成新的圆顶区;固有层与黏膜下层以及黏膜肌层可见大量嗜酸性粒细胞浸润.扫描电镜下,感染组肠黏膜上皮脱落;贝氏莫尼茨绦虫头节呈椭球状,有4个吸盘,无顶突,小沟,表面覆盖一层致密的微绒毛.研究结果表明,肠黏膜增厚,主要是局部黏膜免疫相关细胞在寄生虫虫体表面覆盖的微绒毛的不断刺激下,机体抗感染自身组织增生所致.成年绵羊对抗贝氏莫尼茨绦虫的感染可能是通过黏膜免疫相关组织增生来加强局部免疫力而实现的.     

鸡肠道SGLT1和GLUT2 mRNA表达的组织特异性研究

运用相对定量RT-PCR方法，研究不同肠段Arbor Acre（AA）肉鸡肠道葡萄糖吸收转运主要载体SGLT1和GLUT2mRNA表达的组织特异性。结果发现。随着肠道空间位置的后移，SGLT1 mRNA的表达量逐步降低。十二指肠SGLT1 mRNA的丰度比结直肠高76．19Vo，差异极显著（P〈0．01）；而空肠和回肠SGLT1 mRNA的表达量分别比结直肠高42．86％和38．10％，差异不显著（P〉0．05），但有提高的趋势（P值分别为0．06和0．07）。十二指肠与空肠和回肠相比，SGLTlmRNA的表达量虽然分别高23．33％和27．59％，但差异不显著（P值分别为0．18和0．10）。相对定量分析表明，十二指肠和空肠GLUT2 mRNA丰度非常接近，差异不显著（P〉0．05）。定性研究显示，十二指肠与空肠GLUT2 mRNA丰度高于回肠和结直肠。鸡肠道SGLT1和GLUT2 mRNA表达的组织特异性之生理功能，有待于进一步研究。     

Ultrastructure and alkaline phosphatase activity of the dome epithelium of canine Peyer's patches

The dome epithelium of Peyer's patches from different parts of the intestine of four dogs was examined by scanning and transmission electron-microscopy and by alkaline phosphatase histochemistry on glycol-methacrylate embedded sections. M cells were scattered among more numerous enterocytes in duodenal and jejunal Peyer's patches, but constituted the major cellular component of dome epithelia of the ileal Peyer's patches. Alkaline phosphatase histochemistry demonstrated low enzyme activity in the brush border of M cells, as compared to enterocytes, in the duodenum and jejunum, allowing identification of M cells at the light microscopic level. Alkaline phosphatase activity was too low in ileal enterocytes to permit visualization of M cells. The presence of intrafollicular invaginations of dome epithelium is a consistent finding in duodenal Peyer's patches of the dog and these invaginations were characterized by few M cells, many intraepithelial lymphocytes and strong alkaline phosphatase activity.     

黄秋葵叶粉对海兰褐蛋鸡盲肠微生物及肠道组织结构的影响

 试验旨在研究饲料中添加黄秋葵叶粉对海兰褐壳蛋鸡肠道微生物及肠道组织结构的影响。选取处于同一生产水平的海兰褐壳蛋鸡450只,随机分为5组,每组3个重复,每个重复30只,试验组黄秋葵叶粉添加量分别为3%(T₃)、4%(T₄)、5%(T₅)、6%(T₆),对照组为不添加黄秋葵叶粉组(0%,T₀)。试验预试期1 W,正试期12 W。结果表明日粮中添加黄秋葵叶粉可在一定程度上降低大肠杆菌的数量,促进盲肠中双歧杆菌和乳酸杆菌的增殖,其中以4%添加量效果最好。在42  d和84 d时屠宰,试验组鸡回肠、空肠和十二指肠的肠壁厚度较对照组均有提高,其中84 d时各试验组空肠肠壁厚度极显著高于对照组(P＜0.01);试验组回肠、空肠和十二指肠的绒毛高度(VH)及绒毛高度/隐窝深度(V/C)均显著高于对照组;42 d时,试验组T₃、T₄回肠和各试验组空肠隐窝深度较对照组显著降低(P＜0.05),试验组十二指肠隐窝深度较对照组均有所下降,差异不显著;84 d时,各试验组回肠及T₃、T₄组空肠和十二指肠隐窝深度较对照组显著降低(P＜0.05)。这表明,日粮中添加适量黄秋葵叶粉在一定程度上具有改善蛋鸡肠道微生物菌群和肠道组织结构的作用,其中以4%的添加量效果最好。     

Amylolytic activity in the digestive tract of lambs during the first months after birth

Alpha-amylase activity in duodenal chymus and glucoamylase activity in homogenate and microvilli membranes of enterocytes from duodenum, jejunum and ileum of lambs at an age of 1, 7 and 23 days was studied. Alpha-amylase activity in duodenal chymus increases proportionally with increasing the age of lambs, at 7 and 23 days of age rising 2 and 3 times respectively compared to one-day age. Glucoamylase activity in homogenate and Microvilli membranes increases even at 7 day-age 3-6 times depending on the part of small intestine, then keeping on the whole the same level.     

日粮中添加复合微生态制剂对蛋种鸡肠道pH及微生物的影响

研究日粮中添加复合微生态制剂对蛋种鸡小肠肠道长度、pH及盲肠微生物的影响,试验选用1日龄海兰褐蛋种鸡320只,随机分为4个组,进行16周的试验。试验组日粮是在对照组日粮基础上分别添加50、100、200 g/t的复合微生态制剂组成。试验结果表明:① 与对照组相比, 21日龄时,添加复合微生态制剂组显著降低了蛋种鸡十二指肠、空肠、回肠的相对长度(P<0.05);42日龄时,试验2组的回肠相对长度显著低于对照组(P<0.05); 112日龄时, 试验1组空肠和回肠的相对长度显著低于对照组 (P<0.05),试验3组十二指肠的相对长度显著低于对照组(P<0.05)。②试验1、2组蛋种鸡21日龄空肠和回肠的pH显著低于对照组(P<0.05),试验3组蛋种鸡21、42、112日龄十二指肠、42日龄空肠的pH也显著降低 (P<0.05) 。③添加复合微生态制剂可显著提高蛋种鸡21日龄盲肠乳酸菌的数量(P<0.05),其中试验2组乳酸菌的数量最多,与对照组相比,提高了11.76%,其次是试验3组和试验1组;添加复合微生态制剂对于42和112日龄蛋种鸡的盲肠微生物无显著影响。结果提示,日粮中添加复合微生态制剂能缩短蛋种鸡小肠肠道相对长度,同时降低肠道pH并能改善肠道菌群,对雏鸡的健康生长有促进作用。本试验中添加100 g/t的复合微生态制剂为适宜添加量。     

肉鸡肠道NHE2 mRNA表达的组织特异性与发育性变化

选用遗传背景相同的1日龄父母代雄性Arbor Acre（AA）肉雏鸡120羽,随机分为4个重复,采用相对定量RT-PCR方法,以30日龄AA肉鸡肠道RNA为模板,研究肉鸡肠道钠/氢交换载体2（Sodium hydrogen exchanger 2,NHE2）mRNA表达的组织特异性;以AA肉鸡十二指肠和空肠RNA为模板,研究肉鸡肠道NHE2mRNA表达的发育性变化。结果显示：①AA肉鸡十二指肠和空肠NHE2 mRNA的表达丰度显著高于回肠和结直肠（P〈0.05）,而十二指肠和空肠之间、回肠和结直肠之间无显著差异（P〉0.05）;②AA肉鸡NHE2 mRNA在十二指肠及空肠中的表达具有相同的发育模式,2～16日龄升高,30～44日龄下降,55日龄略微回升;在16和30日龄时的表达丰度显著高于2、44和58日龄（P〈0.05）。以上结果说明：AA肉鸡肠道近端NHE2 mRNA的表达丰度显著高于远端（P〈0.05）。AA肉鸡十二指肠及空肠NHE2 mRNA的表达具有相同的发育模式,表明NHE2mRNA表达受到发育阶段的调控,且在十二指肠和空肠间具有稳定性。     

Ghrelin在成年皖西白鹅小肠内的免疫组化定位研究

采用免疫组化SABC法并结合DAB显色技术研究了皖西白鹅小肠内Ghrelin阳性细胞及其分布。结果：①Ghrelin免疫阳性细胞主要位于小肠的黏膜层，而黏膜下层和肌层未见Ghrelin阳性细胞。这些阳性细胞，胞浆着色，主要有两类，一类为“闭合型”细胞，呈圆形或椭圆形，其顶部不露于腔面，另一类为“开放型”细胞，呈锥体型，细胞顶部达到腔面。②在十二指肠，“开放型”和“闭合型”两种阳性细胞均可观察到，而在空肠和回肠，主要为“闭合型”阳性细胞。产生Ghrelin的细胞在成年皖西白鹅小肠黏膜层有广泛的分布，揭示Ghrelin可能调节小肠的功能。     

捻转血矛线虫中肠超微结构

捻转血矛线虫中肠由单层上皮细胞所组成，未见明确的细胞界限，并向肠腔内伸出相互平行、排列整齐的微绒毛，长约6.5μm，微绒毛中心由纵贯微绒毛并相互平行的微丝构成；细胞核位于细胞中部，核膜清楚，体形大，形状不规则，有一较大的核仁，异染色质凝集成块状，电子致密度甚高。分散于核质中；上皮细胞中部细胞器丰富，有粗面内质网、线粒体、高尔基体及溶酶体；基部为胶原纤维样，并含有丰富的内质网。