Alanyl-glutamine protects the intestinal barrier function in trained rats against the impact of acute exhaustive exercise

Strenuous exercise triggers deleterious effects on the intestinal epithelium, but their mechanisms are still uncertain. Here, we investigated whether a prolonged training and an additional exhaustive training protocol alter intestinal permeability and the putative effect of alanyl-glutamine (AG) pretreatment in this condition. Rats were allocated into 5 different groups: 1) sedentary; 2 and 3) trained (50 min per day, 5 days per week for 12 weeks) with or without 6 weeks oral (1.5 g/kg) AG supplementation; 4 and 5) trained and subjected to an additional exhaustive test protocol with or without oral AG supplementation. Venous blood samples were collected to determine gasometrical indices at the end of the 12-week protocol or after exhaustive test. Lactate and glucose levels were determined before, during, and after the exhaustive test. Ileum tissue collected after all experimental procedures was used for gene expression analysis of Zonula occludens 1 (ZO-1), occludin, claudin-2, and oligopeptide transporter 1 (PepT-1). Intestinal permeability was assessed by urinary lactulose/mannitol test collected after the 12-week protocol or the exhaustive test. The exhaustive test decreased pH and base excess and increased pCO2. Training sessions delayed exhaustion time and reduced the changes in blood glucose and lactate levels. Trained rats exhibited upregulation of PEPT-1, ZO-1, and occludin mRNA, which were partially protected by AG. Exhaustive exercise induced intestinal paracellular leakage associated with the upregulation of claudin-2, a phenomenon protected by AG treatment. Thus, AG partially prevented intestinal training adaptations but also blocked paracellular leakage during exhaustive exercise involving claudin-2 and occludin gene expression.

Environmental enteric dysfunction and growth / Disfunção entérica ambiental e crescimento

Abstract Objective: To describe the current indicators of environmental enteric dysfunction and its association with linear growth deficit and the height-for-age anthropometric indicator. Data sources: Narrative review with articles identified in PubMed and Scopus databases using combinations of the following words: environmental, enteric, dysfunction, enteropathy, and growth, as well as the authors' personal records. Data synthesis: In the last 15 years, new non-invasive markers have been investigated to characterize environmental enteric dysfunction; however, the best tests to be used have not yet been identified. There is evidence that, in environmental enteric dysfunction, a systemic inflammatory process may also occur as a consequence of increased intestinal permeability, in addition to intestinal mucosa abnormalities. Bacterial overgrowth in the small intestine and changes in fecal microbiota profile have also been identified. There is evidence indicating that environmental enteric dysfunction can impair not only full growth but also the neuropsychomotor development and response to orally administered vaccines. It is important to emphasize that the environmental enteric dysfunction is not a justification for not carrying out vaccination, which must follow the regular schedule. Another aspect to emphasize is the greater risk for those children who had height impairment in early childhood, possibly associated with environmental enteric dysfunction, to present overweight and obesity in adulthood when exposed to a high calorie diet, which has been called "triple burden." Conclusions: According to the analyzed evidence, the control of environmental enteric dysfunction is very important for the full expression of growth, development, and vaccine response in the pediatric age group.

Resumo Objetivo: Descrever os indicadores atuais da disfunção entérica ambiental e sua relação com déficit de crescimento linear e com o indicador antropométrico estatura-idade. Fontes dos dados: Revisão narrativa com artigos identificados no PubMed e Scopus com o uso de combinações das seguintes palavras: environmental, enteric, dysfunction, enteropathy e growth e dos arquivos pessoais dos autores. Síntese dos dados: Nos últimos 15 anos, vem sendo pesquisados novos marcadores não invasivos para caracterizar disfunção entérica ambiental. No entanto, ainda não foram identificados os melhores testes a serem usados. Existem evidências de que na disfunção entérica ambiental, além das anormalidades da mucosa intestinal, pode ocorrer também processo inflamatório sistêmico em consequência da maior permeabilidade intestinal. Sobrecrescimento bacteriano no intestino delgado e mudança no perfil da microbiota fecal também estão sendo identificados. Evidências indicam que a disfunção entérica ambiental pode comprometer não somente o pleno crescimento como também comprometer o desenvolvimento neuropsicomotor e a resposta de vacinas administradas por via oral. É importante destacar que a disfunção entérica ambiental não é justificativa para não fazer a vacinação, que deve seguir o calendário normal. Um outro aspecto a ser ressaltado é o risco maior dessas crianças que tiveram comprometimento da estatura na infância precoce, possivelmente associado à disfunção entérica ambiental, apresentarem na idade adulta excesso de peso e obesidade quando expostas a uma dieta rica em calorias, o que tem sido chamado "triple burden". Conclusões: De acordo com as evidências analisadas, o controle da disfunção entérica ambiental é muito importante para plena expressão do crescimento, desenvolvimento e resposta vacinal na faixa etária pediátrica.

Intestinal fructose malabsorption is associated with increased lactulose fermentation in the intestinal lumen / Má absorção intestinal de frutose associa-se com maior fermentação de lactulose na luz intestinal

Abstract Objective: To study fructose malabsorption in children and adolescents with abdominal pain associated with functional gastrointestinal disorders. As an additional objective, the association between intestinal fructose malabsorption and food intake, including the estimated fructose consumption, weight, height, and lactulose fermentability were also studied. Methods: The study included 31 patients with abdominal pain (11 with functional dyspepsia, 10 with irritable bowel syndrome, and 10 with functional abdominal pain). The hydrogen breath test was used to investigate fructose malabsorption and lactulose fermentation in the intestinal lumen. Food consumption was assessed by food registry. Weight and height were measured. Results: Fructose malabsorption was characterized in 21 (67.7%) patients (nine with irritable bowel syndrome, seven with functional abdominal pain, and five with functional dyspepsia). Intolerance after fructose administration was observed in six (28.6%) of the 21 patients with fructose malabsorption. Fructose malabsorption was associated with higher (p < 0.05) hydrogen production after lactulose ingestion, higher (p < 0.05) energy and carbohydrate consumption, and higher (p < 0.05) body mass index z-score value for age. Median estimates of daily fructose intake by patients with and without fructose malabsorption were, respectively, 16.1 and 10.5 g/day (p = 0.087). Conclusion: Fructose malabsorption is associated with increased lactulose fermentability in the intestinal lumen. Body mass index was higher in patients with fructose malabsorption.

Resumo Objetivo: Pesquisar a má absorção de frutose em crianças e adolescentes com dor abdominal associada com distúrbios funcionais gastrintestinais. Como objetivo adicional, estudou-se a relação entre a má absorção intestinal de frutose e a ingestão alimentar, inclusive a estimativa de consumo de frutose, o peso e a estatura dos pacientes e a capacidade de fermentação de lactulose. Métodos: Foram incluídos 31 pacientes com dor abdominal (11 com dispepsia funcional, 10 com síndrome do intestino irritável e 10 com dor abdominal funcional). O teste de hidrogênio no ar expirado foi usado para pesquisar a má absorção de frutose e a fermentação de lactulose na luz intestinal. O consumo alimentar foi avaliado por registro alimentar. Foram mensurados também o peso e a estatura dos pacientes. Resultados: Má absorção de frutose foi caracterizada em 21 (67,7%) pacientes (nove com síndrome do intestino irritável, sete com dor abdominal funcional e cinco com dispepsia funcional). Intolerância após administração de frutose foi observada em seis (28,6%) dos 21 pacientes com má absorção de frutose. Má absorção de frutose associou-se com maior produção de hidrogênio após ingestão de lactulose (p < 0,05), maior consumo de energia e carboidratos (p < 0,05) e maior valor de escore z de IMC para a idade (p < 0,05). As medianas da estimativa de ingestão diária de frutose pelos pacientes com e sem má absorção de frutose foram, respectivamente, 16,1 e 10,5 g/dia (p = 0,087). Conclusão: Má absorção de frutose associa-se com maior capacidade de fermentação de lactulose na luz intestinal. O índice de massa corporal foi maior nos pacientes com má absorção de frutose.

Avaliação da resposta imunológica da mucosa intestinal de frangos de corte desafiados com diferentes sorovares de Salmonella / Evaluation of immune response of the intestinal mucosa in broilers challenged with different Salmonella serovars

Objetivou-se com o presente estudo comparar o efeito de diferentes sorovares de Salmonella na resposta imune local da mucosa do intestino de frangos de corte. Aos sete dias de idade, as aves foram desafiadas com os sorovares S. Enteritidis, S. Typhimurium, S. Senftenberg, S. Mbandaka e S. Minnesota. Foi observado que todos os sorovares testados foram capazes de colonizar o intestino das aves sendo possível o isolamento de Salmonella em suabes de cloaca, 48 h após inoculação. De maneira geral, as aves do grupo controle negativo, que não foram desafiados apresentaram quantidade significativamente menor de células imunológicas na mucosa intestinal do que as aves desafiadas. Porém, verificou-se que os sorovares de Salmonella, utilizados neste estudo, apresentaram diferentes efeitos sobre a dinâmica celular da mucosa do íleo e ceco e afetaram de modo diferente o ganho de peso e ganho médio diário das aves demonstrando distintos graus de patogenicidade. Os sorovares Enteritidis e Typhimurium apresentaram um efeito mais intenso tanto no desempenho quanto na mobilização de células imunológicas na mucosa intestinal de frangos de corte.

The study was designed to compare the effect of different Salmonella serovars in immune response across the count of CD8+ cells, CD4+ cells, goblet cells and macrophages in the gut mucosa of broilers. During the experimental inoculation at 7 day-old were used Salmonella enterica subspecies enterica sorovars Enteritidis, Typhimurium, Senftenberg, Mbandaka and Minnesota. It was observed that all serovars tested were capable of contaminating the poultry being possible counts of Salmonella in cloacal swabs, 48 h after inoculation and into the crop and cecum, at 14 and 20 day-old. Serovars tested had different effects on broiler performance assessed at 20 days. In the mucosa of the ileum and cecum of broilers, it was observed that some of the serotypes increased CD8 + cells, CD4 + cells, goblet cells and macrophages compared to the negative control group both at 14 and at 20 day-old. S. Enteritidis and S. Typhimurium are the serovars that showed the more intense effect in live performance and in the immune system of birds showing pathogenic characteristic; generally the broilers of the negative control showed significantly less immune cells on the intestinal mucosa than broilers inoculated experimentally. However, it was found that the Salmonella serovars used in this study had different effects on the cellular dynamics of the mucosa of the ileum and cecum and differently affect weight gain and average daily gain of poultry showing different levels of pathogenicity.

The Role of Barrier Dysfunction and Change of Claudin Expression in Inflammatory Bowel Disease

No abstract available.

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis

BACKGROUND/AIMS: This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. METHODS: Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. RESULTS: The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%+/-1.2% in controls and was significantly increased to 7.2%+/-1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. CONCLUSIONS: There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability.

Increased Intestinal Epithelial Cell Turnover and Intestinal Motility in Gymnophalloides seoi-Infected C57BL/6 Mice

The changing patterns of goblet cell hyperplasia, intestinal epithelial cell turnover, and intestinal motility were studied in ICR and C57BL/6 mice infected with Gymnophalloides seoi (Digenea: Gymnophallidae). Whereas ICR mice retained G. seoi worms until day 7 post-infection (PI), C57BL/6 mice showed a rapid worm expulsion within day 3 PI. Immunosuppression with Depo-Medrol significantly delayed the worm expulsion in C57BL/6 mice. Goblet cell counts were increased in both strains of mice, peaking at day 1 PI in C57BL/6 mice and slowly increasing until day 7 PI in ICR mice. In C57BL/6 mice infected with G. seoi, newly proliferating intestinal epithelial cells were remarkably increased in the crypt, and the increase was the highest at day 1 PI. However, in ICR mice, newly proliferating intestinal epithelial cells increased slowly from day 1 to day 7 PI. Intestinal motility was increased in G. seoi-infected mice, and its chronological pattern was highly correlated with the worm load in both strains of mice. Meanwhile, immunosuppression of C57BL/6 mice abrogated the goblet cell proliferation, reduced the epithelial cell proliferation, and suppressed the intestinal motility. Goblet cell hyperplasia, increased intestinal epithelial cell turnover, and increased intestinal motility should be important mucosal defense mechanisms in G. seoi-infected C57BL/6 mice.

Hystopathological study of the intestinal epithelium submitted to different times of programmed ischemia and twenty four hours reperfusion

PURPOSE: To investigate the changes in the intestinal epithelium of rats, when submitted to the ischemia of varied time and scheduled reperfusion. METHODS: For this purpose, the following groups were established six groups: control, 10, 20, 30, 40, 60 minutes of ischemia and reperfusion time (24 hours). Their intestines being resected for histopathological analysis: the length and width of the villus, and mitotic index. The nonparametric test Kruskal-Wallis and multiple comparisons test were applied. RESULTS: The qualitatively the intestinal epithelium is regenerated when submitted to different ischemia, and 24 hours reperfusion time. It was observed that morphometry analyzing taking villus length and width and mitotic index as parameter, meaningful alterations were detected. CONCLUSION: The epithelium is regenerated, when subjected to different time planned of ischemia and reperfusion. It was observed: decrease the length and increase the width of the villi, when compared Group VI with I and II, and Group VI with I; increased mitotic index when compared Groups III with I. Every analysis was statistically significant.

Sindrome de intestino irritable: ¿Un trastorno funcional? / [Irritable bowel syndrome: a functional disorder?].

Irritable bowel syndrome is a highly prevalent condition responsible for almost one third of visits to the gastroenterologist and huge expenses for diagnosis, treatment and loss of working days. A unique pathophysiologic mechanism has not been elucidated yet and several possibilities have been proposed such as senso-perception and motor disturbances, the effect of stress and anxiety, serotonin receptor failures, activation of abnormal brain areas and pain modulation differences, among others. The absence of a biological marker has led the investigators to consider this syndrome as an exclusion diagnostic condition, once the organic diseases have been discarded The changes in gut microbiota have recently raised great interest among gastroenterologists. The study of the small intestinal bowel overgrowth syndrome, the effect of antibiotics upon the flora, the recognition of post-infectious irritable bowel syndrome and the action of probiotics, together with the effect of malabsortion of diet carbohydrates have brought some new light in our knowledge. The present update will focus on the published evidence about the subject, bearing in mind that the mechanisms elicited here are only suitable for a subgroup of patients.

Evaluation by computerized morphometry of histopathological alterations of the colon wall in segments with and without intestinal transit in rats / Avaliação por morfometria computadorizada das alterações histopatológicas da parede cólica em segmentos com e sem trânsito intestinal em ratos

PURPOSE: To evaluate histopathological alterations of the colon wall in segments with and without intestinal transit, by computer-assisted imaging, and to correlate these with the length of time diversion. METHODS: Thirty male Wistar rats were subjected to intestinal transit diversion by a proximal colostomy and distal mucosa fistula. The animals were divided into three experimental groups according to how long after the initial surgical procedure they were sacrificed: six, twelve and eighteen weeks. Colon segments with and without transit were subjected to histopathological study. The variables colon crypt length, mucosal ulceration, muscle layer thickness of the muscularis mucosa, submucosa and muscularis propria, vascular congestion, number of caliciform cells, inflammatory grade and degree of inflammation, comparing the two colon segments in the different experimental groups were studied. Intestinal crypt length, muscle layer thickness of the mucosa, submucosa and muscularis propria and caliciform cells were measured by computer-assisted imaging method. Mean equality, variance analysis and correlation tests were used in the statistical analysis, and the significance level was set at 5 percent. RESULTS: Comparison between segments with and without transit showed that the latter presented reduced length of colon crypts and increased muscle layer thickness of the muscularis mucosa, submucosa and muscularis propria. There were greater quantities of ulceration of the mucosal and greater degree of inflammation with increasing time without transit. Mucosal ulceration, submucosal vascular congestion, increased thickness of the submucosal and muscularis propria layers, presence of caliciform cells, inflammatory infiltrate and inflammatory grade correlated significantly with the length of time without transit. CONCLUSIONS: Histological alterations occurred in all layers of the colon wall, in the segments without intestinal transit. Ulcerations...

OBJETIVO: Avaliar por método de imagem assistida por computador as alterações histopatológicas da parede cólica em segmentos providos e desprovidos de trânsito intestinal e relacioná-las ao tempo de exclusão. MÉTODOS: Trinta ratos Wistar machos foram submetidos à derivação do trânsito no cólon esquerdo por meio de colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo o sacrifício ter sido realizado seis, doze e dezoito semanas após o procedimento cirúrgico inicial. Segmentos dos cólons providos e desprovidos de trânsito foram submetidos a estudo histopatológico. Foram analisadas as variáveis: comprimento das criptas cólicas, ulceração na mucosa, espessura das camadas muscular da mucosa, submucosa e muscular própria, congestão vascular, número de células caliciformes e graduação inflamatória comparando os dois segmentos cólicos nos diferentes grupos experimentais. As variáveis, comprimento das criptas intestinais, espessura das camadas muscular da mucosa, submucosa e muscular própria foram mensuradas por método de imagem assistida por computador. Na análise estatística foram utilizados testes de igualdade de médias e medianas, análise de variância e correlação estabelecendo-se nível de significância de cinco por cento. RESULTADOS: A exclusão de trânsito mostrou-se associada à redução do comprimento das criptas cólicas, aumento da espessura das camadas muscular da mucosa, submucosa e muscular própria. Verificou-se maior quantidade de ulcerações na mucosa e maior grau de inflamação com o progredir do tempo de exclusão. Houve correlação significante entre as ulcerações da mucosa, congestão vascular da submucosa, aumento da espessura das camadas submucosa e muscular própria, presença de células caliciformes, infiltrado inflamatório, graduação inflamatória e o tempo de exclusão de trânsito. CONCLUSÕES: Alterações histológicas ocorrem em todas as camadas da parede cólica, em segmentos sem...

Alterations in the intestinal wall due to protein malnutrition in rats: Evaluation of the rupture strength and the tissue's collagen / Alterações da parede intestinal na carência de proteína no rato: Avaliação da força de ruptura e do colágeno tecidual

PURPOSE: To study the effect of protein malnutrition on the intestinal wall of rats by evaluating alterations in the rupture force and dosing tissue collagen in the ileum and distal colon. METHODS: One hundred and twenty rats, that had an average weight of 100g, were used. They received water and a standard diet with 20 percent protein during 7 days for adaptation to the diet itself and to environmental conditions. After that period, the animals were randomly distributed in two groups of 60 rats each: Group 1 - the animals received a control diet with 20 percent casein for 21 days; Group 2 - hypoprotein diet with 2 percent casein for 21 days. After the adaptation period, 12 animals of each group were sacrificed at 5 moments: the beginning of experimental period (M0), 4° day (M1), 7° day (M2), 14° day (M3) and 21° day (M4). The diet to the other rats was maintained until the last sacrifice. The following variables were evaluated: body weight, blood albumin rate, tissue's hydroxyproline, hydroxyproline/total protein ratio and rupture strength in the intestinal wall of the ileum and the distal colon. RESULTS: It was observed that the rupture strength in the ileum segment and distal colon was lower in malnourished animals (Group 2); the loss of mechanical resistance was higher in the distal colon segment than in the ileum probably due to the smaller concentration of tissue collagen in the distal colon. CONCLUSION: Protein malnutrition induces the loss of mechanical resistance of the ileum and distal colon and may be associated with a smaller percentage of collagenous tissue formation in the intestinal wall.

OBJETIVO: Avaliar o efeito da desnutrição protéica na parede intestinal do rato através da medida de força de ruptura e dosagem do colágeno tecidual no íleo e cólon distal. MÉTODOS: Foram utilizados 120 ratos, pesando em média 100g, que receberam durante 07 dias uma dieta padrão, contendo 20 por cento de caseína para adaptação dos animais as condições do biotério. Após esse período os animais foram divididos em dois grupos de 60, o controle denominado grupo um que recebeu a dieta padrão, e o grupo teste denominado grupo dois, que recebeu dieta hipoprotéica contendo 2 por cento de caseína. Os dois grupos receberam suas respectivas dietas por um período de 21 dias. Após esse período iniciou-se o sacrifício seqüencial dos animais em ambos os grupos, em número de 12 animais em cada momento, correspondendo ao dia Zero (MO), 4º dia (M1), 7º dia (M2), 14º dia (M3), e 21º dia (M4) sendo mantida a mesma dieta até o final do sacrifício. Em cada momento foram avaliados o peso corpóreo, albumina sanguínea, hidroxiprolina tecidual, relação hidroxiprolina/proteína tecidual e a força de ruptura no segmento ileal e cólico dos animais. RESULTADOS: Observou-se que a força de ruptura do segmento ileal e do cólon distal foi menor nos animais desnutridos (Grupo 2). A perda da resistência mecânica foi maior no segmento do cólon distal do que no segmento ileal, provavelmente pela menor concentração do colágeno tecidual no cólon distal. CONCLUSÃO: A desnutrição protéica induz a diminuição da resistência mecânica no íleo e no cólon distal associado a diminuição do colágeno tecidual na parede intestinal.

Efeitos hemodinâmicos sistêmicos e regionais da infusão de cristalóides em modelo experimental de choque séptico hipodinâmico / Regional and systemic hemodynamics effects of crystalloids infusion in an experimental model of hypodynamic septic shock

Para estudar os efeitos hemodinâmicos sistêmicos e regionais da expansão volêmica em modelo de choque séptico, vinte e um cães anestesiados e sob ventilação mecânica receberam dose letal de E. coli vivas por via endovenosa, randomizados em três grupos: Ringer lactato 16 ou 32ml/Kg em 30min ou controle e observados 120min. A bacteremia promoveu hipotensão, redução do débito cardíaco, fluxo porta e renal, acompanhados por aumento da extração sistêmica e regional de oxigênio, acidose láctica e aumento dos gradientes veno-arterial, porta-arterial e gastro-arterial de CO2. A expansão volêmica promoveu benefícios parciais e temporários insuficientes para reverter os déficits perfusionais.To study the regional and systemic hemodynamics effects of fluid resuscitation in a model of septic shock. Twenty-one anesthetized and mechanically ventilated dogs received a lethal doses of live E. coli in blood circulation, randomized in three groups: Lactate Ringer 16 or 32ml/kg in 30 min and control and observed 120 min. The bacteremia resulted in hypotension, decrease of cardiac output, portal and renal flow, accompanied by an increase in the systemic and regional oxygen extraction, lactic acidosis and increase in venous-arterial, porto-arterial and gastro-arterial of CO2 gradients. Fluid replacement resulted in partial and temporary benefits unable to restore the perfusional deficits...

Fisiopatología de la diarrea aguda / Physiopathology of acute diarrhea

Es un artículo de revisión de los aspectos importantes de la fisiopatología de la diarrea. Se hace una descripción de la fisiopatología intestinal que incluye la anatomía del intestino y de su superficie de absorción y la estructura funcional de la mucosa intestinal. La fisiopatología normal de los líquidos intestinales. Mecanismo de absorción del agua y los electrólitos. Absorción de sodio por difusión electrogénica, unido al ion cloro, intercambio con el ion hidrógeno y unido a sustancias orgánicas como glucosa, aminoácidos y algunos oligopéptidos; secreción intestinal de agua y electrólitos. Control intracelular de la secreción. Mediadores y moduladores extracelulares del transporte intestinal. Factores que aumentan la absorción y reducen la secreción. Factores que estimulan la secreción y reducen la absorción Mecanismo fisiopatológico de la diarrea. Clasificación de la diarrea infecciosa aguda: acuosa secretoria y osmótica; diarrea con sangre invasiva y no invasiva

Permeabilidad intestinal en alcohólicos sin daño hepático / Intestinal permeability in alcoholics without hepatic damage

Methods: Thirty seven male subjects were studied, 18 controls and 19 alcoholic: All subjects underwent an anthropometric assessment and dietary history. Lactulose/mannitol test was performed during the third day of abstinence in alcoholics. After an 8 hour overnight fast, subjects drank 200 ml of a solution containing 56 g lactulose and 5 g mannitol. Subsequently, urine was collected during the following 5 hours, where both sugars were measured by gas chromatography. Results: Median values of lactulose/mannitol ratio were similar in alcoholics and controls (0.011, range 0.005-0.071 vs 0.014, range 0.005-0.027 respectively). However, absolute urinary excretion of both lactulose and mannitol was lower in alcholics. There was no relationship betwwen nutritional status and urinary excretion of lactulose, mannitol or lactulose/mannitol ratio. Conslusion: In this alcoholic patients, no changes were observed in intestinal permability

Análise morfométrica do intestino delgado de esquistossomóticos / Morphometric studies on the mucosa from thje small intestine of schistosomiasic patients with portal hypertension

Foram estudados aspectos histológicos e morfométricos da mucosa do intestino delgado de 22 pacientes esquistossomótiocs hépato-esplêncos antes e após cirurgia de reduçÝo da pressÝo portal, sendo analisados aspectos histológicos gerais como congestÝo, edema, infiltraçÝo inflamatória, fibrose e número de granulomas da mucosa, e morfométricos como número, disposiçÝo e forma das vilosidades, alturas da mucosa e das vilosidades, número de células caliciforme e de Paneth e densidade de eosinófilos. Na análise histológica, verificou-se uma reduçÝo na congestÝo e edema da mucosa após a cirurgia. No estudo morfométrico, constatou-se posteriormente à cirurgia, o aumento estatísticamente significativo, no número de vilosidades digitiformes e foliáceas, e a tendendica à reduçÝo, nas formas em clava e achatadas. Conclui-se que o esquistossomótico hépato-esplênico apresenta alteraçSes estruturais na mucosa do intestino delgado, no entanto, há uma tendência para recuperaçÝo do padrÝo mucoso normal após a reduçÝo da pressÝo portal

Aspectos clínicos da síndrome de má-absorçäo em pacientes infectados pelo HIV: valor da d-xilose como marcador de alteraçäo funcional da mucosa jejunal / Clinical aspects of the malabsorption syndrome in HIV infected patients: value of d-xilose as a marker of jejunal mucosal functional alteration

Os autores submeteram 30 pacientes infectados pelo HIV (Grupo I - portadores assintomáticos; Grupo II - AIDS, emagrecimento e diarréia crônica; Grupo III - AIDS e emagrecimento; Grupo IV - grupo controle) à avaliaçäo funcional da mucosa jejunal (Teste da D-xilose), e ao estudo histomorfométrico da mucosa jejunal através de material obtido por biópsia por cápsula. Correlacionaram as alteraçöes do teste da D-xilose com achados histomorfométricos com a intençäo de associar alteraçöes morfológicas às funcionais, integrando estrutura e funçäo da superfície absortiva do intestino delgado nesses pacientes. A correlaçäo entre esses achados näo foi obtida, mas a presença de alteraçöes funcionais no teste da D-xilose mesmo em portadores assintomáticos enfatiza as alteraçöes precoces do enterócito na infecçäo pelo HIV, mesmo na ausência de alteraçöes morfológicas. O teste da D-xilose, de baixo custo e fácil execuçäo, poderia ser útil na avaliaçäo da mucosa absortiva e na escolha do tipo de dieta para cada paciente, podendo prevenir complicaçöes nutricionais adicionais.

Colon epithelial electrical responses to acute hyposia and reoxygenation in vitro

Electrogenic epithelial transport depends on oxidative metabolism. Acute hypoxia and subsequent reoxygenation effects on short-circuit current (Isc), transepithelial potential difference (PD) and tissue resistivity (TR) of rat distal colon were assessed. The tissue was mounted in an Ussing chamber filled with Ringer-HCO3 -solution at 37 degrees Celsius and bubbled with 95 per cent O2- 5 per cent CO2 which was switched to 95 per cent N2- 5 per cent CO2 for inducing hypoxia; afterwards normal oxygenation was resumed. The effect of 5, 10, 15 and 20 min-hypoxic periods was assessed in isolataed mucosa preparations. Recovery was complete after 10- and 15-min hypoxia, but not after 20-min hypoxia. After 5-min hypoxia, an overshoot of Isc and PD was seen on reoxygenation. This effect was further characterized comparatively in mucosa-submucosa and isolated mucosa preparations. In the former (n=10), control values were Isc= 71,7 + 8,6 muA,. cm-2, PD = 9,7 + 1,6 mV and TR = 134,9 + 13,6 (. cm2. A 5-min hypoxia reduced Isc by 47.2 + 7,3 per cen+t and PD by 61,5 + 4,9 per cent. Peak values on reoxygenation were 28,1 + 4,1 per cent for Isc and 16,8 + 5,4 per cent for PD, over controls values. In the osilated mucosa (n=9), control values were Isc= 52,04 + 5,5 muA. cm-2, PD = 5,0 + 0,8 mV and TR = 101,04 + 10,5 (. cm2. In hypoxia, Isc decreased by 64,5 + 7,6 per cent and PD by 57,2 + 7,8 per cent. On reoxygenation peak values of 78,0 + 19,0 per cent and 87,5 + 17,1 per cent, respectively, were seen. The response to a 5 min-hypoxia was comparable, but that to reoxygenation was weaker and slower, in mucosa-submucosa than in isolated mucosa preparations. This may be explained by a hindrance to oxygen diffusion caused by the submucosal tissue. TR did not change with any period of hypoxia tested, but decreased slightly (8,9 + 1,3 per cent) upon reoxygenation in the mucosa-submucosa preparations. Ouabain (10(-3)M) markedly blunted the response to reoxygenation. We conclude that hypoxic periods of 20 min lead to irreversible functional deterioration. Hypoxia decreases electrogenic transepithelial pumping, which may allow sodium to accumulate intracellularly and, if the hypoxia is short enough to prevent damage to the epithelium, increase sodium pump activity when oxygenation is resumed.