E2 prostaglandins modulate cell proliferation in the small intestinal epithelium of the rat.

Groups of Sprague-Dawley rats were administered 1 mg/kg indomethacin subcutaneously, indomethacin subcutaneously plus 200 micrograms/kg oral 15-R-15 methyl-prostaglandin E2 (MePGE2) or oral MePGE2 twice daily for 10 days. The animals were treated with antibiotics to prevent mortality. Two control groups were used: control 1 was given placebo and control 2 was treated with antibiotics. All rats were killed 4 h after injection of a metaphase blocker, and the proliferative activity of the distal small intestine was examined in histological sections by means of the cumulative mitotic index (MI). A reduction in the number of villous cells was observed in the rats given antibiotics (p < 0.05 vs. control 1). The small intestinal villi of the rats treated with indomethacin had fewer cells than those of both control groups (p < 0.05) whereas the crypts contained more cells (p < 0.05) and had a higher MI than those of the controls (p < 0.05 vs. controls 1 and 2). These changes were reverted by the prostaglandin analogue. The number of cells of the small intestinal crypts and the cumulative MI in the rats who received indomethacin and the prostaglandin analogue were similar to controls, and they were significantly lower than the values observed in the animals treated with indomethacin (p < 0.05). The animals treated with the prostaglandin analogue and placebo developed a marked hyperplasia of the small intestinal villi (p < 0.05 vs. both control groups), but the atrophy of the villi induced by indomethacin was not prevented by simultaneous administration of the analogue.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mucin histochemistry of virus-induced duodenal adenomas in guinea fowl

Summary The type of mucoproteins in virus-induced duodenal adenomas in guinea fowl were compared with those in the normal duodenal mucosa. The mucin-producing cells in the latter contained a mixture of acid and neutral mucins. Neutral and sulphomucins prevailed in the crypts and in the lower part of the villi, while the amount of the sialomucins increased pro-gressively toward the tip of the villi. In the adenomas, goblet cells were more numerous and were unevenly distributed. In their mucin profile the deeply located tumor glandular structures resembled normal crypts and lower parts of the villi and superficial portions of the adenomas were similar to the upper part of the villi. Qualitative changes in the mucin secretion with deviation from the normal vertical distribution of mucin types were rarely observed. The histochemical study carried out supplemented the histological characterization of the virus-induced duodenal adenomas and contributed to the elucidation of some aspects of their histogenesis.     

Apoptosis and cell proliferation of small intestinal villi in mitomycin C-treated rats

Mitomycin C (MMC) therapy often causes toxicity affecting the small intestine. We investigated the relationship between pathological manifestations and cell death, or the proliferation of small intestinal villi in rats treated with MMC. The length of the villi, apoptosis, and cell proliferation were evaluated in the small intestine at 3, 7, and 11 days after MMC treatment by the TUNEL method, BrdU-immunohistochemistry, and transmission electron microscopy. In MMC-treated rats, the body weight decreased until day 7 and recovered from day 8, while most rats had watery stools from days 4 to 7. The villi were the shortest on day 7 and were still shorter on day 11 than in the control group. The highest incidence of TUNEL-positive cells in the small intestinal crypts was observed on day 3, and the number decreased thereafter to reach the control level on day 11. The percentage of BrdU-labeled cells was the highest on day 3 and the lowest on day 7, but recovered to the control level on day 11. The clinical symptoms caused by MMC treatment are consistent with the changes of villous length that reflect the viability of stem cells in the small intestinal crypts about 4 days earlier.     

Medium-chain triglycerides enhance mucous secretion and cell proliferation in the rat

Background  The specific purpose of this study was to investigate the effects of medium-chain triglycerides (MCTs) on intestinal cell proliferation and mucous secretion of the small intestine in the rat. Methods  Rats were fed chow diet and given MCTs or the same weight of corn oil (5 g/kg per day) by gavage daily for 2 weeks, and then tissue samples of the small intestines were harvested. Leptin concentration in the small intestine was measured. Cell proliferation and apoptosis in the small intestine was determined by immunohistochemistry. Diamine oxidase (DAO) activity was measured by colorimetric assay. Results  In rats fed only chow diet (normal rats), the number of goblet cells per villi was 14.2 ± 0.75 in the jejunum and 15.2 ± 1.12 in the ileum. The number of goblet cells increased significantly in rats given MCTs compared with rats given corn oil or normal rats. Ki-67-positive cells were detected on the entire villi and the crypts in the small intestine. Furthermore, the proliferative index and the apoptotic index were also significantly greater in rats given MCTs than rats given corn oil or normal rats. Moreover, DAO activity and leptin concentration in the small intestine were significantly greater in rats given MCTs than rats given corn oil or normal rats. Conclusions  MCTs enhance cell proliferation of the intestinal epithelium and mucous secretion from goblet cells in the small intestine. These effects may protect the gut in patients suffering from inflammatory bowel disease or enterogenous infection.     

Initial kinetic changes of prostaglandin E2-induced hyperplasia of the rat small intestinal epithelium occur in the villous compartments

This study was performed to further identify the sequence of cell kinetics that occurs in the development of gastric and intestinal epithelial hyperplasia after orally administered prostaglandins of the E series. A high-dose, short-treatment schedule was used to examine the initial effects on kinetic parameters in the rat small intestinal epithelium. Groups of rats were killed after a single dose of oral prostaglandin E2 at 1 h after in vivo labeling with [methyl-3H]thymidine and during continued treatment at 6, 12, 24, 48, 72, and 96 h. As evidenced by autoradiography, the earliest change produced by prostaglandin E2 was an increased cellularity of the villous compartment (p less than 0.05 after 24 h). There was no change of labeling index of the villous compartment or of the leading edge of labeled cells within 24 h. At 48 h, the increased cellularity was accompanied by a significantly elevated labeling index of the villi. Throughout the study period no significant differences were observed between groups in the number of cells or labeling indices in the jejunal crypts, or in cellular input from the crypts to the villi. Epithelial turnover time in the placebo and treatment groups was 69 and 71 h, respectively. To exclude the possibility that prostaglandin E2 initially affects cell birth rate and mean cell cycle time, a metaphase blocker was given after 4 days of treatment in a second study. Animals were killed after 0, 0.5, 1.0, 1.5, and 2.5 h. The rate of entry into mitoses was 8.1% cells/h in controls compared with 8.2% cells/h in treated rats. The distribution of mitoses within crypts was identical in the two groups and the mean cell cycle time was 13.6 and 13.2 h, respectively. Also in this study there were trophic changes of the villi. It is concluded that the hyperplasia produced by oral prostaglandin E2 starts in the villi of the small intestine and is initiated by reduced cell exfoliation from the villous tips. Previously recorded retention of cellular elements in villi and crypts, increased cellularity of the proliferative compartments, and reduced mitotic index are secondary events.     

Advances in the prenatal diagnosis of hematologic diseases

Prenatal diagnosis of hematologic diseases can now be performed with fetal blood, fetal amniotic fluid cell DNA, and fetal chorionic villi DNA. Some hemoglobinopathies can be detected by all three methods, and the choice will depend on the available obstetric and laboratory techniques, as well as the time of presentation of the pregnancy. Hopefully, further development of molecular probes and techniques will soon expand these options to all of the globin disorders. Detection of coagulation disorders in utero currently requires samples of pure fetal blood. Gene cloning is accomplished for some (factor IX and antithrombin III) and is underway for others (factor VIII), and further investigation is necessary to determine whether deficiencies in these gene products are due to gene deletion or to mutant genes linked to polymorphic restriction enzyme sites of diagnostic use. Thus, molecular biology may be applied to prenatal diagnosis of the clotting problems, but this has not yet been accomplished. Disorders affecting the number and/or function of erythrocytes, leukocytes, and platelets can be diagnosed by analysis of fetal blood. Blood samples will continue to be required until more is known about the molecular biology of hematopoiesis. Syndromes that can be diagnosed by chromosome studies should be revealed in cultures of amniotic fluid cells, fetal blood lymphocytes, and chorionic villi cells. Cultured cells can be examined for karyotypes, Y-chromatin, spontaneous or induced chromosome breakage, DNA repair, SCEs, and translocations. The techniques for culturing amniotic cells and fetal blood white cells are established, and those for growing cells from chorionic villi are improving rapidly. Direct preparations of cells from villi only may suffice for some of the above analyses. The study of hematologic disease in utero has thus come full circle, from the use of amniotic cells to determine the sex in X-linked disorders, to fetal blood sampling for the analysis of gene products, then back to amniocentesis for DNA, and now earlier in gestation to chorionic villi. All of this has occurred in less than ten years, and it is anticipated that developments in the next ten years will be equally dramatic. The future should bring all prenatal testing into the first trimester, use molecular probes, and provide for both early diagnosis and early treatment of genetic hematologic disease.     

Chronic pancreatitis in African diabetics

Steatorrhea due to chronic pancreatitis was found in 23% of a consecutive series of 107 new African diabetics; 3 had pancreatic calcification. Of 16, 14 had definitely abnormal exocrine secretion on pancreatic function testing using secretin-pancreozymin stimulation. The morphology and function of the small intestine were normal by local standards. When compared with diabetics without steatorrhea they weighed less, their fasting blood sugars were lower, and their insulin requirements were greater. High alcoholic intake might be a significant cause, but the incidence was similar in the diabetics without steatorrhea. No evidence of childhood or adult malnutrition was established. The etiology of this high incidence of chronic pancreatitis among African diabetics remains unexplained.This work formed part of Dr. Wicks' thesis for his MD degree (Birmingham).This work was supported by a generous research grant from the University of Rhodesia.     

Mechanism of Excretion of Iron by the Small Intestine: an Experimental Study in Rats with Normal and Abnormal Mucosae

The findings in the present study have demonstrated the presence of two distinct mechanisms of iron excretion by the small intestine in rats. Loss of cell bound iron is the principal pathway of excretion and takes place as epithelial cells are shed off from the tips of villi. The available evidence suggests that the epithelial cells of the mucosa sequestrate iron from a storage pool which might be identical to the labile iron store in man. Transferrin bound iron makes a small contribution to the total loss. An abnormally large amount of iron was excreted in the small intestine of rats infested with Nippostrongylus brasiliensis. At the same time an unduly large amount was also sequestrated by the intestines of these rats. These facts were attributed to increased population of maturing cells in the crypts and the rapid rate of renewal of the villous epithelium.
The morphological appearances of the intestinal villi of the infested rats have a resemblance to those in human subjects with coeliac disease. It is, therefore, suggested that these observations may have some bearing on the status of iron balance in patients suffering from coeliac disease.     

Distribution of constitutive nitric oxide synthase in the jejunum of adult rat

AIM: To study the distribution of the constitutive nitric oxidesynthase (NOS) in the jejunum of adult mt.METHODS: The distribution of endothelial NOS (eNOS) wasdetected by immunohistochemistry. Immunofluorescencehistochemical dual staining technique were used forstudying the distribution of neuronal NOS (nNOS) andeNOS. The dual stained slides were observed under aconfocal laser scanning microscopeRESULTS: Positive neuronal NOS (nNOS) and endothelialNOS (eNOS) cells were found to be distributed in laminapropria of villi, and the epithelial cell was not stained. eNOSwas mainly located in subrnucosal vascular endothelia,while nNOS was mainly situated in myenteric plexus. Somecells in the villi had both nNOS and eNOS. More than 80 %of the cells were positive for both nNOS and eNOS, the restcells were positive either for nNOS or for eNOS.CONCLUSION: The two constitutive nitric oxide synthasesam distributed differently in the jejunum of rat. nNOSdistributed in myenteric plexus is a neurotransmitter in thenon-adrenergic non-cholinergic (NANC) inhibitory nerves.eNOS distributed in endothelial and smooth muscle cells ofblood vessesels plays vasodilator role. eNOS and nNOS arecoexpressed in some cells of lamina propria of villi. NOgeneratedl by those NOS is very important in thephysiological and pathological process of small intestine.     

Bacteriological and histological studies of the small intestine of rats treated with mecamylamine

Rats were injected intraperitoneally with mecamylamine (Inversine) in doses that were believed to have reduced peristaltic activity in the small intestine. Large numbers of Escherichia coli were present throughout the lumen of the small intestine of animals treated for two or three days and killed within three hours of the last dose of the drug. Histological changes in the small intestinal mucosa of these animals included an increase in the number of goblet cells and shortening and thickening of the villi. Bacteria invaded the intestinal wall of some of the animals. Animals killed 24 hours after the last dose of the drug showed no significant change from the normal controls.

The findings support the hypothesis that bacteria are removed mechanically from the normal small intestine by peristalsis. Certain of the histological changes are similar to those seen in the small intestine in malabsorptive conditions in man and the relationship between hypomotility, the bacterial population, and malabsorption is discussed.

     

酒精通过抑制肠上皮干细胞增殖损伤肠上皮的更新修复能力

目的 研究酒精对肠上皮干细胞(ISC)和肠上皮更新修复能力的影响。方法 将18只C57BL/6小鼠随机分为对照组(n=9)和酒精处理组(n=9)。采用Gao-Binge法制备慢性酒精中毒模型。在造模成功后,腹腔注射5-溴-2-脱氧脲苷(BrdU),分别在注射后2 h、24 h和72 h取小肠组织,采用免疫组化法检测BrdU阳性细胞和ISC特异性标志物Lgr5表达。结果 与对照组小鼠比,酒精处理组小鼠小肠绒毛高度显著缩短、萎缩;酒精处理组小鼠ISC细胞Lgr5表达显著弱于对照组;酒精处理组小鼠每个肠隐窝BrdU阳性细胞数量为(3.50±0.65)个/肠隐窝,显著少于对照组【(7.90±1.08)个/肠隐窝,P＜0.05】;在注射BrdU 后2 h、24 h和72 h,酒精处理组小鼠小肠BrdU阳性细胞迁移距离分别为(66.67±1.60)μm、(219.40±12.11)μm和(313.90±9.76)μm,显著短于对照组【分别为(111.10±1.60)μm、(319.00±10.04)μm和(625.90±3.34)μm,P＜0.05】。结论 酒精通过抑制ISC引起肠上皮细胞增殖和迁移能力下降,从而损伤肠上皮的更新修复能力,导致肠上皮屏障功能障碍。     

Distribution of constitutive nitric oxide synthase in the jejunum of adult rat

AIM：To study the distribution of the constitutive nitric oxide synthase(NOS) in the jejunom of adult rat.METHODS:The distribution of endothelial NOS(eNOS) was detected by immunohistochemistry.Immunofluorescence histochemical dual stainging technique were used for studying the distribution of neuronal NOS( nNOS) and eNOS,The dual stained slides were observed under a confocal laser scanning microscope.RESULTS:Positive neuronal NOS(nNOS) and endothelial NOS(eNOS) cells were found to be distributed in lamina propria of villi,and the epithelial cell was not stained,eNOS was mainly located in submucosal vascular endothelia while nNOS was mainly sityated in myenteric plexus.Some cells in the villi had both nNOS and eNOS.More than 80% of the cells were positive for both nNOS and eNOS,the rest cells were positive either for nNOS or for eNOS.CONCLUSION:The two constitutive nitric oxide synthases are distributed differently in the jejunum of rat.nNOS distributed in myenteric plexus is a neurotransmitter in the non-adrenergic non-cholinergic(NANC)inhibitory nerves eNOS distributed in endothelial and smooth muscle cells of blood vessels plays vasodilator role .eNOS and nNOS are coexpressed in some cells of lamina propria of villi.NO genearted y those NOS is very important in the physiological and pathological process of small intestine.     

Colonic adenomas: Stereology and growth mechanisms

Stereologic methods were used to determine the amount of growth of colonic adenomatous polyps. Epithelial surfaces were increased from 12 to 226 times compared with the normal mucosa of origin, including the epithelium of the crypts. The number of cells was increased from 12 to 370 times. The supposed villi of the polyps are in reality branched folia, and the crypts between them are slit-like, permitting flow of ingesta through them. The increase in the number of cells is not primarily dependent on mitotic activity but more on amitotic nuclear fragmentation Supported in part by NIH grant AM 19172.     

Cell cycle distribution of proliferative and functional cells of the rat jejunum after treatment with oral E2 prostaglandins

Proliferative and functional epithelial cells were isolated from jejunal specimens of the rat by means of vibrational treatment combined with differential air insufflation. This method gave a good separation between superficial cells of the villi and the crypt cells, as evaluated by flow cytometry, morphology, cytology, and incorporation of radioactive thymidine into DNA. Groups of Sprague-Dawley rats (260 g) were treated twice daily for 11 days with oral placebo, 15(R)15-methyl-prostaglandin E2 in the range of 0.125-2 mg X kg-1, or 5 mg X kg-1 natural PGE2. Isolated crypt cells and superficial cells of the jejunal villi were then analysed by flow cytometry. Morphometric measurements were performed on sections of some jejunal specimens not submitted to vibrational treatment. The cell cycle distribution of crypt cells was unaffected by treatment with the prostaglandin analogue despite the presence of trophic changes. The proportion of crypt cells in G2/M phase was slightly but significantly reduced in rats given natural PGE2 compared with controls. The cell cycle distribution of villus cells was not affected by prostaglandin treatment. Trophic changes in the absence of increased DNA synthesis (S phase) or increased mitotic activity suggests that the hyperplasia observed after prostaglandin treatment is due to a reduced cell loss and/or slower migration time of epithelial cells.     

Water filtration of the forearm in short- and long-term diabetes mellitus

Summary Blood flow and capillary filtration coefficient (CFC) were measured by strain-gauge plethysmography on the upper and lower third of the forearm in 9 normal subjects and 29 well regulated patients with diabetes mellitus of varying duration (less than 10 years, 10 to 20 years, and more than 20 years). There was no difference in blood flow in the four groups, but CFC was significantly increased in long-term diabetics (duration above 20 years) when measured at the distal part of the forearm near the wrist. Calculations showed that this was probably due to the relatively high contribution of connective tissue in this part of the forearm. Increased water filtration in connective tissue in long-term diabetics is in accordance with earlier findings of a lowered subcutaneous interstitial fluid albumin concentration in long-term diabetics, this being explained by an increase in net water outflux from the microcirculation.     

Tritiated thymidine radioautographic study on the origin and renewal of secretin cells in the rat duodenum

The origin and renewal of secretin cells in the duodenum were investigated using the unlabeled antibody peroxidase-antiperoxidase technique and radioautography in rats killed at various times after single or multiple injections of [3H]thymidine. Secretin cells were spatially distributed from the upper crypt to the villus tip, being particularly numerous in the upper two-thirds of the duodenal villi. After a single injection of [3H]thymidine, there were no labeled secretin cells, indicating a lack of self-replicating activity. After repeated injections of the isotope, labeled secretin cells appeared and increased in number. They first occurred at the upper part of the crypt and the lower part of the villus, and later at the villus tip. All these cells were found to be labeled after continuous labeling for 120 h, which is considered to be the renewal time for this cell population.     

The development of the fetal rat intestine and its reaction to maternal diabetes. I. Morphometrical analysis in normal conditions

In rodents, the fetal intestine develops rapidly during the last 5 days of gestation. The present investigation describes the events which occur in the duodenum, jejunum and ileum of fetal Wistar rat from day 16.5 to 21.5. The first villi and microvilli as well as endocrine cells already appear at 17.5 days in the duodenal mucosae. Goblet cells are detected at 18.5 days. The structure of the intestinal mucosa at 21.5 days is similar to that of adults. The evolution was quantified by morphometric analysis. The external and inner circumference, the length of the villi profile and the increased absorption area due to the villi profile were measured. We demonstrated that the total enlargement of the luminal surface area due to the villi and the microvilli in the duodenum of the fetus at 21.5 days is similar to that in the adult duodenum. This morphometric analysis could be used to detect possible disturbances in the development of the fetal intestine.     

人类轮状病毒感染新生小鼠肠道外组织的病理变化

目的了解人类轮状病毒(RV)全身扩散后对机体的影响,为临床的防治提供有价值参考。方法选用对人类RV敏感的健康新生昆明小鼠,经灌胃与腹腔注射两种途径接种RV,3d后处死小鼠,光镜下观察各脏器病理变化;电镜下观察肝脏的病理变化;各脏器原位杂交,原位PCR检测RV,并与健康小鼠比较。结果光镜下:RV口服组小肠绒毛、胃固有层、心肌细胞有改变;RV腹腔注射组除上述改变外,肝,肾也有改变;电镜下:肝细胞线粒体肿胀、凝集病变尤为明显,细胞核固缩-崩解,粗面内质网扩张,肝细胞中存在大量脂滴和空泡;毛细胆管明显扩张,微绒毛脱落。原位杂交:RV口服组小肠上皮细胞,RV腹腔注射组肠、肾近曲小管上皮细胞呈阳性;原位间接PCR:RV口服组小肠绒毛、肠腺细胞、肾近曲小管和集合管上皮细胞呈阳性,RV腹腔注射组肠、肾、肝、心脏、胰呈阳性。结论RV一旦向全身扩散,可侵犯除肠之外的多个器官组织,提示人类RV也可能具有一定的泛嗜性。     

Administration of prostaglandin E1 in diabetics and non-diabetic patients with severe Fontaine stage IIb arterial occlusive disease

The success in therapy of prostaglandin E1 intra-arterially and intravenously applied to diabetics and non-diabetics with PAOD, stages IIb-IV according to Fontaine, was scrutinized in a city hospital primarily concerned with geriatrics, metabolism, and angiology. All the patients included were examined in retrospective studies with regard to the improvement of their situations during their stays in hospital and--in addition to that--a part of them prospectively some time after their stays in hospital. In all, 99 patients were included in the retrospective examination of which there were 60 diabetics and 39 non-diabetics. Of the 60 diabetics 53 were in stage IV, 5 in stage III, and 2 in stage IIb while in case of non-diabetics 26 were in stage IV, 10 in stage III, and 3 in stage IIb. 50 of the diabetics and 27 of the non-diabetics were treated intra-arterially. The prospectively orientated post-observation included 38 diabetics and 24 non-diabetics. The results of the retrospective examination revealed a significantly superior efficiency of intra-arterially applied PGE1 compared with the intravenous application, both, with regard to the reduction of needed analgesics and the improvement of the clinical situation. A comparison between intra-arterially treated diabetics and non-diabetics showed a significantly higher rate of success of the diabetics regarding to the improvement of the clinical situation. Concerning the prospective post-examination: due to their PAOD the diabetics took significantly more often analgesics at the time of their post-examination than the non-diabetics. Also concerning the development of their clinical situations the diabetics turned out to have worse results than the non-diabetics, however, the differences were not significant in this case.