Efeitos da isquemia e da reperfusão na ocorrência de apoptose no jejuno em eqüinos / Effects of ischemia and reperfusion in apoptosis occurrence in equine jejunum

Investigou-se o resultado da isquemia, da congestão e da reperfusão na ocorrência de apoptose. Modelos de obstrução vascular total - artériovenosa e venosa - foram induzidos no jejuno por 2h, seguidos de reperfusão durante 12h. As amostras de tecidos foram processadas, e os dados analisados pelo teste de Friedman. As colorações de Schorr e hematoxilina-eosina evidenciaram anoiquia, condensação da cromatina, fragmentação nuclear e celular características de apoptose. índices apoptóticos significativamente mais baixos ocorreram em 2h e 12h de reperfusão na região das vilosidades, e tenderam à estabilidade na região das criptas. A apoptose constitui uma importante parcela na perda de células intestinais durante a isquemia, congestão e reperfusão, além da necrose.

The effects of ischemia and reperfusion in apoptosis occurrence in equine were studied. Intestinal samples were taken and biopsy specimens evaluated. Data were analyzed by Friedman test. Schorr and hematoxilin-eosine staining showed shrunken anoykic cells, chromatin condensation, nuclear and cellular fragmentation typical of apoptosis. Significant lower apoptotic index occurred at 2h and 12h of reperfusion in the villous region. No difference was observed in the crypt region. Apoptosis constitutes an important part of cell loss in addition to necrosis.

Gene chip analyses reveal differential genetic responses to iron deficiency in rat duodenum and jejunum

Previous studies revealed novel genetic changes in the duodenal mucosa of iron-deprived rats during post-natal development. These observations are now extended to compare the genetic response to iron deficiency in the duodenum versus jejunum of 12-wk-old rats. cRNA samples were prepared from the duodenal and jejunal mucosa of three groups each of control and iron-deficient rats and hybridized with RAE 230A and 230B gene chips (Affymetrix). Stringent data reduction strategies were employed. Results showed that several genes were similarly induced in both gut segments, including DMT1, Dcytb, transferrin receptor 1, heme oxygenase 1, metallothionein, the Menkes copper ATPase (ATP7A), tripartitie motif protein 27, and the sodium-dependent vitamin C transporter. However, a subset of genes showed regulation in only one or the other gut segment. In duodenum only, gastrokine 1, trefoil factor 1 and claudin 2 were induced by iron-deficiency. Other genes previously identified were only regulated in the duodenum. Overall, these studies demonstrate similarities and distinct differences in the genetic response to iron deprivation in the duodenum versus jejunum and provide evidence that more distal gut segments also may play a role in increasing iron absorption in iron-deficiency anemia.

Morphological and functional alterations of the intestine of rats with iron-deficiency anemia

The present study was designed to assess the intestinal absorption of D-xylose and jejunal morphometry in rats with iron-deficiency anemia. Male Wistar rats were randomly divided into a control group (diet containing 50 mg Fe/kg, N = 12) and an anemic group (diet containing <5 mg Fe/kg, N = 12). The animals were housed in individual metabolic cages and deionized water and diet were provided ad libitum for 6 weeks. Hemoglobin and hematocrit were determined at 0, 2, 4, and 6 weeks. At the end of the study the rats were submitted to a D-xylose absorption test (50 mg/100 g body weight) and sacrificed and a jejunal specimen was obtained for morphometric study. At the end of the study the hemoglobin and hematocrit of the anemic rats (8.7 ± 0.9 g/dl and 34.1 ± 2.9 percent, respectively) were significantly (P < 0.05) lower than those of the controls (13.9 ± 1.4 g/dl and 47.1 ± 1.5 percent, respectively). There was no statistical difference in D-xylose absorption between the anemic (46.5 ± 7.4 percent) and control (43.4 ± 9.0 percent) groups. The anemic animals presented statistically greater villus height (445.3 ± 36.8 µm), mucosal thickness (614.3 ± 56.3 µm) and epithelial surface (5063.0 ± 658.6 µm) than control (371.8 ± 34.3, 526.7 ± 62.3 and 4401.2 ± 704.4 µm, respectively; P < 0.05). The increase in jejunum villus height, mucosal thickness and epithelial surface in rats with iron-deficiency anemia suggests a compensatory intestinal mechanism to increase intestinal iron absorption.

Comparison of duodenal and jejunal disaccharidase levels in patients with non ulcer dyspepsia.

AIMS: This study was conducted to compare the duodenal and jejunal disaccharidase levels in the same individual with duodenal ulcer or non ulcer dyspepsia. METHODS: Thirty seven patients (duodenal ulcer--11, non-ulcer dyspepsia--26) were included in the study. Endoscopic biopsy samples were obtained from jejunum and duodenum using pediatric colonofibroscope. RESULTS: Levels of jejunal disaccharidases were significantly higher than the duodenal disaccharidases. CONCLUSIONS: An estimate of jejunal disaccharidases can be had by multiplication of duodenal disaccharidased by a factor 1.48 for lactase, 1.50 for sucrase and 1.56 for maltase.

Effect of rotavirus infection on lipid composition and glucose uptake in infant mouse intestine.

OBJECTIVE: To study the effect of rotavirus infection on lipid composition and glucose uptake in small intestine of infant mice. METHODS: Thirty six 7-day old balb/c mice were given 50 mL (100 ID50) rotavirus suspension orally; 36 control animals received only normal saline. Body weight of animals was recorded. Six animals in each group were sacrificed on days 0, 1, 3, 5, 7 and 10 post-inoculation (pi). Intestines were removed, everted and homogenized in ice-cold saline. Cholesterol and phospholipid content, glucose uptake and alkaline phosphatase in the jejunum and ileum were determined. RESULTS: Rotavirus infection led to a significant decrease in body weight with on days 3 and 5 pi as compared to controls, and to an increase in cholesterol and phospholipid content of the intestine. Uptake of glucose also increased significantly. Alkaline phosphatase activity was significantly reduced on days 3 and 5 pi as compared to controls. CONCLUSION: This study provides characterization of the lipid composition and uptake of glucose in infant mice small intestinal segments during rotavirus infection.

Permeability characteristics of piperine on oral absorption--an active alkaloid from peppers and a bioavailability enhancer.

Piperine, [1-[5-[1,3-benzodioxol-5-yl]-1-oxo-2,4, pentadienyl] piperidine], is a pungent alkaloid present in Piper nigrum Linn, and P. longum Linn. It is shown to enhance the bioavailability of various structurally and therapeutically diverse drugs. A concise mechanism responsible for its bioavailability enhancing action is poorly understood. This study is an effort to understand the absorption dynamics of piperine in intestine on oral absorption. It encompasses intestinal everted sacs as an experimental model. Cycloheximide treatment and exclusion of Na+ salts from incubating medium were the variables used. Absorption half life, absorption rate, absorption clearance and apparent permeability co-efficient were computed from the data. Experiments to denote physico-chemical characteristics of this moiety exhibited that it is a weak base, highly lipophilic in nature with partial solubility in aqueous media. It exhibited passive diffusion constituting non-saturable absorption kinetics. Transport of piperine was not resisted by UWL and was proposed to be absorbed through transcellular pathway. It displayed short absorption clearance and high apparent permeability co-efficient. Data thus obtained suggested that piperine is absorbed very fast across the intestinal barrier. It may act as an apolar molecule and form apolar complex with drugs and solutes. It may modulate membrane dynamics due to its easy partitioning thus helping in efficient permeability across the barriers.

Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus

The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE) histochemical technique in whole-mount preparations. Neuronal density was 1,500 + 116 neurons/cm2 (mean + SEM) in the esophagus, 8,900 + 1,518 in the stomach, 9,000 + 711 in the jejunum and 13,100 + 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 mum2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease.

Jejunal absorption of trypsin in rat and guinea pig

Gut absorption is one of the first requirements for the study of the mechanism of a possible anti-inflammatory action of proteases, such as orally administered trypsin. Porcine trypsin absorption was studied in isolated jejunal loops of rats (female Holtzman and male Wistar) and guinea pig (males) by open-loop perfusion. Trypsin was dissolved in Tyrode solution and the solution perfused at a rate of 0.5 ml/min, at 37§C. Trypsin activity, total protein, and sodium and potassium concentrations were assayed in the jejunal effluent; the values were unchanged throughout the experiments, which lasted 45 to 120 min. Using a high sensitivity ELISA (i.e. pg/ml), trypsin absorption could be demonstrated by determination of the enzyme in the mesenteric venous blood (samples of 0.5 ml); the enzyme concentration increased with time of perfusion. The linear range-specificity for intact trypsin varied from 1 to 500 ng/well. In this assay polyclonal antibodies prepared against trypsin-TLCK were utilized. Whereas trypsin concentration in the perfused lumen was practically constant at 0.12 mg/ml, the concentration of absorbed trypsin in mesenteric vein blood increased from about 100 ng/ml at time zero to 1.8 µg/ml, after 45 min of perfusion. Histological and ultrastructural examination of the jejunal mucosa before and after perfusion revealed that the brush-border, basal membrane, and junctional complexes were fully preserved, thus eliminating the possibility that trypsin might have destroyed the structures, thereby reaching the blood circulation. The present data indicate that µg quantities of trypsin were absorbed by the isolated jejunal loop of the rat

Transporte jejunal eletrogênico da glicose em ratos com deficiência de niacina / Jejunal electrogenic transport of glucose in rats with niacin deficiency

A absorçäo jejunal eletrogênica ativa da glicose foi estudada pelo método da perfusäo intestinal "in vivo", infundido-se soluçöes de glicose com concentraçäo crescente (2,5;5,0; 10,0; 20,0; 50,0 e 100,0 mM/L) em 15 cm de jejuno isolado de 12 ratos com deficiência de niacina. Os resultados dos animais carentes foram comparados com os de 12 animais que ingeriram dieta controle na mesma quantidade ingerida pelo seu par carente. A diferença de potencial transmural média em cada concentraçäo infundida de glicose foi estatisticamente menor nos animais carentes, em relaçäo aos controles. Além disso, nos ratos carentes, o Km foi maior (16,1 x 12,7), enquanto que Pdmax foi menor que o dos controles (12,5 x 19,4), respectivamente, demonstrando a ocorrência da depleçäo do transporte ativo eletrogênico da glicose, na carência de niacina. Uma possível explicaçäo para este achado seria a depleçäo das fontes de energia intra-enterocitária

Técnica simples e rápida de intubaçäo para obtençäo de secreçäo jejunal / Simple and rapid technique of intubation for obtention of jejunal secretion

Este estudo foi proposto para introduzir uma técnica nova e mais rápida de intubaçäo para obtençäo de secreçäo jejunal. A utilizaçäo de um "fio guia" introduzido no lúmen da sonda propicia uma maior rigidez ao conjunto, o que facilita a progressäo manual da sonda. Foi analisado comparativamente o tempo dispendido na passagem da sonda até o intestino delgado entre a técnica convencional e a do "fio guia" em 40 lactentes. O tempo de intubaçäo foi menor com a técnica do "fio guia" (x = 15,4 min) do que a convencional (x = 91,0 min) (p < 0,05). Para simplificar o método, a determinaçäo da posiçäo do tubo foi realizada pela observaçäo da mudança de coloraçäo do líquido de drenagem da extremidade proximal da sonda e da determinaçäo do pH do aspirado intestinal

Disposition of norepinephrine and epinephrine in jejunum of WLH chicken.

Disposition of (-)-norepinephrine and (-)-epinephrine in jejunum of WLH chicken was studied using oil-immersion technique. The relative rate of different routes of disposition of catecholamines was in the following order: for (-)-NE COMT greater than or equal to MAO greater than or equal to U2 greater than U1, for (-)-Epi U2 greater than or equal to COMT greater than MAO greater than U1. The role of enzymatic degradation is almost equal to that of uptake processes for (-)-Epi, but it was greater for (-)-NE.

Absorçäo de glicose por um segmento de colo distal interposto entre cotos de intestino delgado após ressecçäo de 80% do jejuno-ileo: estudo experimental em ratas / Glucose absorption by a segment of distal colon interposed between two segments of small bowel after 80%

Os autores se propöem a estudar o comportamento de um segmento de colo distal interposto no trajeto do intestino delgado ressecado, em relaçäo à absorçäo de glicose, comparando-o a um segmento semelhante de colo mantido em sua posiçäo normal. Utilizando o método de passagens rápidas e sucessivas de uma soluçäo de glicose de concentraçäo conhecida por um segmento de colo distal interposto após ressecçäo de 8% do comprimento do jejuno-íleo e por um segmento semelhante de colo distal em sua posiçäo normal no mesmo animal, logrou-se comparar as curvas de absorçäo de glicose entre estes dois segmentos e relacioná-las com curvas padräo de absorçäo de glicose do intestino delgado e do colo de ratos. Os resultados mostraram que o segmento de colo interposto absorve glicose em maior quantidade quando comparado ao colo distal mantido em sua posiçäo normal

Cinética do transporte jejunal de glicose em ratos com deficiência de niacina / Kinetics of jejunal glucose transport in niacin deficient rats

Estudou-se a cinética da absorçäo jejunal da glicose pelo método da perfusäo intestinal in vivo em 180 ratos jovens, 90 dos quais receberam dieta deficiente em niacina e o restante dieta controle. Foram infundidas sete soluçöes de glicose (5, 10, 20, 40, 80, 160 e 320 mM), uma para cada grupo de animais. Determinou-se o V max. e o Km aparente para os animais controles e carentes. Verificou-se que os animais carentes absorveram menos glicose em cada concentraçäo infundida e que seu Vmax e Km (133.3 µM/15 cm e 92.2 mM/1, respectivamente) foram menores em relaçäo aos animais controles (294.1 µM/15 cm e 171.8 µ M/1, respectivamente). Com o modelo experimental utilizado, pode-se afirmar que na deficiência de niacina ocorre menor absorçäo de glicose

Método para a medida da absorçäo da glicose por segmentos isolados de jejuno, íleo e colo distal in vivo: estudo experimental em ratas / Method for in vivo glucose absorption by isolated segments of jejunal, ileun and distal colon

A síndrome do intestino curto possui algumas alternativas para o tratamento cirúrgico. Entre as que melhores benefícios apresentam estäo as interposiçöes de segmentos anisoperistáticos de delgado ou a interposiçäo de colo. O Curso de Pós-Graduaçäo em Técnica peratória e Cirurgia Experimental, entre as suas linhas de pesquisa, dedica-se ao estudo das adaptaçöes morfo-funcionais de segmentos de colo interposto entre cotos de segmento delgado após resseçöes amplas de seu comprimento. Em continuidade a essa linha de pesquisa, o presente o trabalho dá a sua contribuiçäo para a realizaçäo da padronizaçäo e adaptaçäo para as condiçöes do nosso meio e das necessidades da linha de pesquisa, da técnica de passagens sucessivas para a dosagem de absorçäo de glicose por segmentos de jejuno, íleo e colo distal. O método mostrou-se viável, prático e pouco onoroso, cumprindo as premissas da proposta inicial. Os resultados mostraram também que, dentro da metododizaçäo empregada, o jejuno e íleo absorvem quantidades de glicose semelhantes estatísticamente, na unidade de tempo e de comprimento. Mostram, também, que o colo absorve comparativamente menos glicose na unidade de tempo e de comprimento que segmentos equivalentes de jejuno e íleo. O colo apresenta uma distribuiçäo heterogênea de absorçäo sendo maior até o quinto período, revelando talvés uma saturaçäo dos processos biológicos envolvidos...

Rotavirus identification in jejunal juice and stools of acute and chronic forms of infantile gastroenteritis

The present study investigates, by means of a combined enzyme immunoassay for rotaviruses and adenoviruses (EIARA), the occurrence of rotaviruses in stools and jejunal juices from 31 children with acute diarrhea and 18 with chronic diarrhea. Stools from 8 acute cases contained rotaviruses (26%). In two of these cases rotaviruses were also detected in the jejunal juice. In the chronic diarrhea group we identified rotaviruses in the stools of one patient and in the jejunal juice of another. Some of the electropherotypes of the rotaviruses identified showed different patterns of RNA migration. Abnormalities of the jejunal mucosa were characterized in 6 acute rotavirus-positive cases. No morphological or functional abnormalities of the intestinal mucosa were observed in the chornic diarrhea rotavirus-positive cases

The influence of lactation on L-proline absorption from small intestine in the albino rat.

Intestinal absorption of L-proline was studied in control and lactating rats from jejunum and ileum by in vivo method and presented per unit dry weight and per unit length of the respective segment. L-proline absorption was found to be significantly reduced in lactating animals as compared to the virgin controls. The results were discussed in light of serosal to mucosal ratio. By in vitro method also jejunal and ileal uptake of L-proline were found to be significantly reduced in lactating animals as compared to the virgin controls.