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.

Glutamine protects intestine against ischemia-reperfusion injury by alleviating endoplasmic reticulum stress induced apoptosis in rats

Abstract Purpose Glutamine, as an essential part of enteral nutrition and parenteral nutrition agent, has been widely recognized to be a kind of important intestinal mucosa protectant in clinical practice and experimental research. However, the mechanisms of its protective effects are still not fully understand. Consequently, this study aimed to explore the potential mechanism of glutamine on ischemia-reperfusion (I/R) injury induced endoplasmic reticulum (ER) stress in intestine. Methods An experimental model of intestinal I/R in rats was established by 1 hour occlusion of the superior mesenteric artery followed by 3 hours of reperfusion. Morphologic changes of intestinal mucosa, apoptosis of epithelial cells, and expression of intestinal Grp78, Gadd153, Caspase-12, ATF4, PERK phosphorylation (P-PERK) and elF2αphosphorylation(P-elF2α) were determined. Results After I/R, the apoptotic index of intestinal mucosa epithelial cells observably increased with notable necrosis of intestinal mucosa, and the expressions of Grp78, Gadd153, Caspase-12, ATF4, P-PERK and P-elF2αall were increased. However, treatment with glutamine could significantly relieve intestinal I/R injury and apoptosis index. Moreover, glutamine could clearly up-regulate the expression of Grp78, restrain P-PERK and P-elF2α, and reduce ATF4, Gadd153 and Caspase-12 expressions. Conclusion Glutamine may be involved in alleviating ER stress induced intestinal mucosa cells apoptosis.

Effects of anti-TNF-α in experimental diversion colitis

Abstract Purpose: To evaluate the effects of infliximab on the inflammation of the colonic mucosa devoid from fecal stream. Methods: Twenty-four rats were submitted to a Hartmann's procedure. They remained for 12 weeks with the fecal derivation to development of diversion colitis on excluded colorectal stump. After this period, they were divided into 3 groups: one group received intervention with saline (2.0 mL / week), other group infliximab at doses of 5 mg/kg/week and the other 10 mg/kg/week for five consecutively weeks. Concluded the intervention period, the animals were euthanized to remove colon segments with and without fecal stream. Colitis was diagnosed by histological analysis and the degree of inflammation by validated score. The neutrophilic infiltrate was evaluated by tissue expression of myeloperoxidase identified by immunohistochemical. The tissue content of myeloperoxidase was measured by computer-assisted image analysis. Results: The inflammatory score was high in colonic segments without fecal stream. The intervention with infliximab reduced the inflammatory score in excluded colonic segments. The content of myeloperoxidase was reduced in colonic segments of animals treated with infliximab mainly in high concentrations. Conclusion: Intervention with infliximab reduced the inflammation and the neutrophil infiltrate in colonic segments devoid of the fecal stream.

A suplementação com quercetina previne mudanças em células imunorreativas à serotonina e caspase-3 do jejuno de ratos diabéticos / Quercetin supplementation prevents changes in the serotonin and caspase-3 immunoreactive cells of the jejunum of diabetic rats

ABSTRACT BACKGROUND: Serotonin (5-HT) is present in the epithelial enterochromaffin cells (EC), mast cells of the lamina propria and enteric neurons. The 5-HT is involved in regulating motility, secretion, gut sensation, immune system and inflammation. OBJECTIVE: Evaluate the effects of diabetes and quercetin supplementation on serotoninergic cells and its cell loss by apoptosis in jejunal mucosa of streptozotocin-induced diabetic rats (STZ-rats). METHODS: Twenty-four male Wistar rats were divided into four groups: normoglycemic (C), normoglycemic supplemented with 40 mg/day quercetin (Q), diabetic (D) and diabetic supplemented with 40 mg/day quercetin (DQ). After 120 days, the jejunum was collected and fixated in Zamboni's solution for 18 h. After obtaining cryosections, immunohistochemistry was performed to label 5-HT and caspase-3. Quantification of 5-HT and caspase-3 immunoreactive (IR) cells in the lamina propria, villi and crypts were performed. RESULTS: The diabetic condition displayed an increase of the number of 5-HT-IR cells in villi and crypts, while decreased number of these cells was observed in lamina propria in the jejunum of STZ-rats. In the diabetic animals, an increased density of apoptotic cells in epithelial villi and crypts of the jejunum was observed, whereas a decreased number of caspase-3-IR cells was observed in lamina propria. Possibly, quercetin supplementation slightly suppressed the apoptosis phenomena in the epithelial villi and crypts of the STZ-rats, however the opposite effect was observed on the 5-HT-IR cells of the lamina propria. Quercetin supplementation on healthy animals promoted few changes of serotoninergic function and apoptotic stimuli. CONCLUSION: These results suggest that quercetin supplementation mostly improved the serotonergic function affected by diabetes maybe due to antioxidant and anti-inflammatory properties of quercetin.

RESUMO CONTEXTO: A serotonina (5-HT) está presente nas células epiteliais enterocromafins (CE), nos mastócitos da lâmina própria e nos neurônios entéricos. A 5-HT está envolvida na regulação da motilidade, secreção, nocepção intestinal, sistema imunológico e inflamação. Objetivo: Avaliar os efeitos do diabetes e da suplementação de quercetina sobre a função serotoninérgica e a perda celular por apoptose na mucosa jejunal de ratos diabéticos induzidos por estreptozotocina (ratos STZ). MÉTODOS: Vinte e quatro ratos Wistar machos foram divididos em quatro grupos: normoglicêmico (C), normoglicêmico suplementado com quercetina 40 mg/dia (Q), diabético (D) e diabético suplementado com quercetina 40 mg/dia (DQ). Após 120 dias, o jejuno foi coletado e fixado na solução de Zamboni por 18 horas. Após a obtenção de cortes em criostato, a imuno-histoquímica foi realizada para marcar 5-HT e caspase-3. A quantificação de células imunorreativas (IR) à 5-HT e caspase-3 foram realizadas na lâmina própria, vilosidades e criptas. RESULTADOS: A condição diabética ocasionou um aumento do número de células 5-HT-IR nas vilosidades e criptas, enquanto que na lâmina própria houve uma redução dessas células, no jejuno de ratos STZ. Nos animais diabéticos, foi observada uma densidade aumentada de células apoptóticas no epitélio do jejuno, tanto nas vilosidades quanto nas criptas, por outro lado um número reduzido de células caspase-3-IR foi observado na lâmina própria. Possivelmente, a suplementação de quercetina suprimiu ligeiramente os fenômenos de apoptose no epitélio de vilosidades e criptas do jejuno de ratos STZ, no entanto, o efeito oposto foi observado nas células 5-HT-IR da lâmina própria. A suplementação com quercetina em animais saudáveis promoveu poucas alterações na função serotoninérgica e nos estímulos apoptóticos. CONCLUSÃO: Estes resultados sugerem que a suplementação de quercetina melhorou principalmente a função serotoninérgica afetada pelo diabetes, talvez devido às propriedades antioxidantes e anti-inflamatórias da quercetina.

Effect of copaiba oil in intestinal mucosa of rats submitted to hypovolemic shock / Efeito do óleo de copaíba na mucosa intestinal de ratos submetidos ao choque hipovolêmico

ABSTRACT Background: Hypovolemic shock is a common disease in polytrauma patients and may develop ischemia in various organs, increasing morbidity and mortality. The bowel is usually most affected by this condition. Aim: To evaluate the effects of copaiba oil on the intestinal mucosa's injury of rats submitted to hypovolemic shock. Method: Fifteen rats were divided into three groups: sham - simulated surgery; ischemia - animals submitted to hypovolemic shock; and copaiba - animals submitted to hypovolemic shock previously treated with copaiba oil. Mean blood pressure, arterial blood gas after shock induction, degree of intestinal lesion and villus length were evaluated. Results: The sham presented the lowest values of lactate and PaCO2 and the highest values of mean arterial pressure, pH and bicarbonate in relation to the other groups. The degree of mesenteric lesion was zero in the sham group; 3.00±1.00 in the ischemia group; and 3.00±0.71 in the copaiba group. The villus length was 173.60±8.42 in the sham, 142.77±8.33 in the ischemia and 143.01±9.57 in the copaiba group. There was a significant difference between the sham and the other groups (p<0.05); however, there not significant difference between groups Ischemia and copaiba. Conclusion: Administration of copaiba oil did not reduce the intestinal mucosa lesion of rats after hypovolemic shock.

RESUMO Racional: O choque hipovolêmico é situação comum em pacientes politraumatizados, podendo acarretar isquemia de vários órgãos, aumentando a morbimortalidade. O intestino é geralmente um dos órgãos mais afetados por essa condição. Objetivo: Avaliar os efeitos do óleo de copaíba na lesão da mucosa intestinal de ratos submetidos ao choque hipovolêmico. Métodos: Quinze ratos foram distribuídos em três grupos: Sham - operação simulada; isquemia - submissão ao choque hipovolêmico; e copaíba - submissão ao choque hipovolêmico previamente tratados com óleo de copaíba. A pressão arterial média, a gasometria arterial após a indução do choque, o grau da lesão intestinal e o tamanho das vilosidades foram avaliados. Resultados: O grupo sham apresentou os menores valores de lactato e PaCO2 e os maiores valores de pressão arterial média, pH e bicarbonato em relação aos demais grupos. O grau de lesão mesentérica foi de zero no sham; 3,0±1,00 no grupo isquemia; e 3,0±0,71 no da copaíba. O comprimento dos vilos foi de 173,60±8,42 no grupo sham, 142,77±8,33 no da isquemia e 143,01±9,57 no da copaíba. Houve diferença significante entre o grupo sham e os demais grupos (p<0.05); contudo, não houve diferença estatística entre os grupos submetidos ao choque hipovolêmico. Conclusão: A administração do óleo de copaíba não reduziu a lesão da mucosa intestinal de ratos submetidos ao choque hipovolêmico.

Oxidative stress assessment in intestine of newborn rats submitted to hypoxia and reoxygenation with tadalafil

Abstract Purpose: To evaluate the functional and structural response of tadalafil effects in the intestinal mucosa, using an experimental model of hypoxia and reoxygenation injury in rats. Methods: The animals were divided into 4 groups: CTL, H/R, H/R+Td and M+Td. The newborn rats allocated in groups H/R, H/R+Td and M+Td were submitted twice a day, to a gas chamber with CO2 at 100% for 10 minutes and afterward reoxygenation with O2 at 98% for 10 minutes, in the three first days of life. Tadalafil dose was given to newborn of group H/R+Td and to the pregnant rat of group M+Td. Histological analysis was made with hematoxylin-eosin technique and oxidative stress through nitrite and nitrate levels and lipid peroxidation. Results: The histological analysis showed a reduction of mucosa alterations in the groups that received tadalafil. In the oxidative stress evaluation, occurred an increase of NO levels and less lipidic peroxidation in the ileum segments that received tadalafil. Conclusion: Tadalafil provides tissue protection when administered independently to both, pregnant or newborns.

Enemas with mesalazine increase the tissue contents of mucins in the colonic mucosa devoid of fecal stream

Abstract Purpose: To evaluate the inflammatory reaction and measure the content of mucins, in the colonic mucosa without fecal stream submit to intervention with mesalazine. Methods: Twenty-four rats were submitted to a left colostomy and a distal mucous fistula and divided into two groups according to euthanasia to be performed two or four weeks. Each group was divided into two subgroups according daily application of enemas containing saline or mesalazine at 1.0 g/kg/day. Colitis was diagnosed by histological analysis and the inflammatory reaction by validated score. Acidic mucins and neutral mucins were determined with the alcian-blue and periodic acid of Schiff techniques, respectively. Sulfomucin and sialomucin were identified by high iron diamine-alcian blue technique. The tissue contents of mucins were quantified by computer-assisted image analysis. Mann-Whitney test was used to analyze the results establishing the level of significance of 5%. Results: Enemas with mesalazine in colonic segments without fecal stream decreased the inflammation score and increased the tissue content of all subtypes of mucins. The increase of tissue content of neutral, acid and sulfomucin was related to the time of intervention. Conclusion: Mesalazine enemas reduce the inflammatory process and preserve the content of mucins in colonic mucosa devoid of fecal stream.

Evaluation of growth performance and gastro-intestinal parameters on the response of weaned piglets to dietary organic acids

ABSTRACT Two experiments (E) were carried out to evaluate the effects of fumaric acid and an acidifier blend [composed by calcium formate, calcium lactate and medium-chain fatty acids (capric and caprylic)] in piglet diets containing colistin (40 ppm) or halquinol (120 ppm) on performance, diarrhea incidence (E1), organs relative weight, pH values, intestinal morphometry and microbiota (E2). In E1, 192 and E2, 24 piglets weaned at 21-day-old were randomly assigned to blocks with 2x2 factorial arrangement of treatments [absence or presence of fumaric acid x absence or presence of acidifier blend], six replicates of eight (E1) and one piglet per pen (E2). For E1, the treatments were control (CD): no acidifier product + 40 ppm of colistin, FA: fumaric acid in absence of acidifier blend, AB: acidifier blend in absence of fumaric acid and, AF+AB: presence of fumaric acid and acidifier blend. For E2, the pre-starter I diet were used and the same treatments as E1 evaluated. No treatment effects (P>0.05) were observed on performance, diarrhea incidence (E1), gut pH values and duodenum morphometry of piglets (E2). However, the addition of AB increased (P<0.05) large intestine relative weight and, FA addition decreased (P<0.05) pancreas relative weight, jejunum villi height and, total coliform and E. coli counts in cecum. The inclusion of FA and AB in diets containing colistin or halquinol did not improve performance, although FA exerted an inhibitory effect on cecum microbiota.

Dietas altas en grasas y sus efectos sobre el intestino / Diets high in fats and their effects on the intestine

El objetivo de esta revisión fue exponer el conocimiento actual sobre la relación existente entre dietas altas en grasa (DAG), alteraciones morfológicas de la mucosa intestinal, efectos inflamatorios y cáncer intestinal. Las DAG inicialmente producen aumento de la microbiota patógena, lo que reduce la cantidad y calidad de la secreción de los exocrinocitos caliciformes, disminuyendo la efectividad de la barrera intestinal. Las bacterias y sus lipopolisacaridos (LPS) promueven la secreción de citoquinas proinflamatorias activando vías de inflamación, que a su vez afectan la integridad de las uniones intercelulares alterando la barrera intestinal. Lo anterior, permite que los LPS ingresen a la lámina propia y circulación sanguínea produciendo inflamación local y sistémica. Así mismo, las DAG generan efectos nocivos en la morfología y función de la mucosa gastrointestinal lo que podría favorecer el desarrollo de cáncer. Lo anterior, podría deberse a que el consumo de DAG es capaz de aumentar la proliferación de células de la mucosa y el número y proliferación de células madres tumorales en el intestino.

The aim of this review was to present current knowledge about the relationship between high fat diets (HFD), morphological alterations of intestinal mucosa, inflammatory effects and intestinal cancer. The HFD initially produces an increase in the pathogenic microbiota, which reduces quantity and quality of secretion of goblet cells, decreasing the effectiveness of intestinal barrier. Bacteria and their lipopolysaccharides (LPS) stimulate the secretion of proinflammatory cytokines by activating inflammation pathways, which in turn affect the integrity of intercellular junctions by changing intestinal barrier. The above allows the LPS enter to lamina propria and blood circulation producing local and systemic inflammation. Likewise, HFD generate deleterious effects on morphology and function of gastrointestinal mucosa, which could favor the development of cancer. This could be due to the fact that consumption of HFD is capable of increasing proliferation of mucosal cells and number and proliferation of tumor stem cells in the intestine.

Efeitos da sinvastatina na mucosite gastrointestinal induzida por 5-fluorouracil em ratos / Effects of simvastatin on 5-fluorouracil-induced gastrointestinal mucositis in rats

RESUMO Objetivo: examinar os efeitos da sinvastatina na mucosite gástrica e intestinal após o tratamento com 5-fluorouracil (5-FU), determinados pela expressão de citocinas e histologia em ratos. Métodos: ratos pesando 270±15g foram divididos em dois grupos. O grupo 5-FU+salina foi tratado com 5-FU (50mg/kg) mais solução salina a 0,9% por gavagem uma vez ao dia por cinco dias. O grupo 5-FU+sinvastatina foi tratado com 5-FU (50mg/kg), mais sinvastatina (10mg/kg), da mesma forma. Foi feita a eutanásia dos animais no sexto dia. O estômago e o intestino foram fotografados e removidos para exame. Dosagens séricas de TNF-a, IL-1ß, IL-6 e histopatologia (coloração HE) do estômago e intestino foram realizadas. Resultados: o peso corporal diminuiu em ratos no grupo 5-FU+salina. A sinvastatina não inibiu a perda de peso induzida pelo 5-FU. Danos significativos da mucosa no estômago e no jejuno foram observados em ratos que receberam apenas 5-FU. As dosagens séricas de citocinas foram significativamente menores no grupo 5-FU+sinvastatina do que no grupo 5-FU (p<0,05). A sinvastatina causou efeitos protetores significativos contra as lesões da mucosa gástrica e jejunal induzidas por 5-FU. Conclusão: a sinvastatina atenua a mucosite gástrica e intestinal relacionada à terapêutica com 5-FU. Nossos dados encorajam futuros estudos pré-clínicos e clínicos sobre a utilidade das estatinas na prevenção da mucosite gastrointestinal.

ABSTRACT Objective: simvastatin has pleiotropic anti-inflammatory and immunomodulatory effects potentially usefull to prevent chemotherapy-induced gastrointestinal mucositis. Studies on this are scarce. This study aimed to examine the effects of simvastatin on gastric and intestinal mucositis after 5-fluorouracil (5-FU) treatment in rats. Methods: rats weighing 270±18g were divided into two groups. The 5-FU+saline group (5-FU/SAL) rats were treated with 5-FU (50mg/kg) plus 0.9% saline orally (gavage) once daily for five days. The 5-FU+simvastatin (5-FU/SIMV) group was treated with 5-FU (50mg/kg), plus simvastatin (10mg/kg), in the same way. The rats were euthanased on the sixth day, then their stomach and intestine were photographed and removed for exams. Dosages of serum TNF-a, IL-1ß, IL-6 and histopathology were done for stomach and intestine. Results: body-weight was significantly lower in rats treated with 5-FU+saline than the weight loss of the 5-FU/SIMV group rats. TNF-a expression was lower in 5-FU/SIMV group (172.6±18pg/ml) than in 5-FU/SAL (347.5±63pg/ml). Serum IL-1b was lower in 5-FU/SAL group (134.5±23pg/ml) than in 5-FU/SIMV (48.3±9pg/ml). Serum IL-6 was 61.8±15pg/ml in 5-FU/SIMV and 129.4±17pg/ml in 5-FU/SAL groups. These differences were significant (p<0.05). Mucosal damage in stomach and jejunum were observed in rats receiving 5-FU alone. In the stomach and jejunum, simvastatin caused significant protective effects against 5-FU-induced mucosal injury. Conclusion: simvastatin attenuated gastric and intestinal mucositis related to 5-FU therapeutics in animal model. These data encourage forthcoming clinical studies addressing the usefulness of statins in the prevention and treatment of gastrointestinal mucositis.

Tissue sulfomucin and sialomucin content in colon mucosa without intestinal transit subjected to intervention with Curcuma longa (curcumin)

Abstract Purpose: To measure the tissue sulfomucin and sialomucin content of the colon mucosa without fecal flow, subjected to intervention with curcumin, and the influence of the concentration used and the intervention time. Methods: Thirty-six rats were subjected to proximal right colostomy and distal mucous fistula. They were divided into two groups according to whether sacrifice was performed two or four weeks after the intervention. Each group was divided into three subgroups according to the enema applied daily: saline alone; curcumin at 50 mg/kg/day or curcumin at 200 mg/kg/day. Acid mucins were diagnosed using the Alcian blue technique. The mucin content was quantified by means of computer-assisted image analysis. The significance level of 5% was used throughout (p < 0.05). Results: There were dose-related increases in the quantities of sulfomucins in the animals subjected to interventions with curcumin, both after two weeks (p < 0.00001) and after four weeks (p < 0.00001). There were increases in sialomucin quantity that were concentration-related (p < 0.00001) and time-related (p < 0.00001). Conclusion: Curcumin enemas increase the quantity of acid mucins in the intestinal flow in the excluded colon, with dose and time dependency.

Claudin-3 and occludin content in the glands of colonic mucosa devoid from fecal stream submitted to topical intervention with oil extract of Curcuma longa

Abstract Purpose: To evaluate the inflammatory intensity and measure the tissue content of the proteins claudin-3 and occludin in the colonic mucosa without fecal stream submit to intervention with curcumin. Methods: Thirty-six rats were submitted to a proximal colostomy and a distal mucous fistula and divided into two groups according to sacrifice to be performed two or four weeks. Each group was divided into three subgroups according daily application of enemas containing saline, curcumin at 50 mg/kg/day or 200 mg/kg/day. Colitis was diagnosed by histological analysis. Claudin-3 and occludin were determined by immunohistochemistry. The tissue content of claudin-3 and occludin were quantified by computer-assisted image analysis. Mann-Whitney, Student t and ANOVA tests were used to analyze the results establishing the level of significance of 5% for both (p<0.05). Results: Curcumin at both concentrations reduces the inflammation and preserves the tissue content of the proteins claudin-3 and occludin, which was related to the concentration used and to the time of the intervention. Conclusion: The application of enemas with curcumin reduces inflammation and preserves the tissue content of the proteins claudin-3 and occludin in the colonic mucosa devoid from the fecal stream.

Probiotic therapy reduces inflammation and improves intestinal morphology in rats with induced oral mucositis

Abstract The aim of the present study was to evaluate the effect of systemic administration of probiotics (PROB) on the progression of experimentally induced oral and intestinal mucositis in rats immunosuppressed by chemotherapy (5-fluorouracil: 5-FU). Twenty-four rats were divided into the following groups (n=6): GC (control), GPROB, G5FU and G5-FU/PROB. Groups GPROB and G5-FU/PROB received 1 g of probiotic incorporated into each 100 g of feed (Bacillus subtilis, Bifidobacterium bifidum, Enterococcus faecium and Lactobacilllus acidophilus), beginning 30 days before oral mucositis induction. Groups G5FU and G5-FU/PROB received 60 mg/kg of 5-FU on days 0 and 2. The left oral mucosa of each animal was irritated by mechanical trauma (days 1 and 2). On days 3 and 7, three animals from each group were sacrificed, and their oral mucosa and small intestine were biopsied and processed for histopathological analysis. Groups G5-FU and G5-FU/PROB showed ulcerated oral lesions at day 3, with progression in group G5-FU and regression in group G5-FU/PROB at day 7. Histologically, less severe signs of inflammation in the oral mucosa were observed in group G5-FU/PROB than in group G5-FU. Regarding the intestine, villus-related defects of lesser magnitude were observed in group G5-FU/PROB, compared with group G5-FU. Group GPROB showed greater villus height than group GC. It can be concluded that probiotic supplementation reduced oral and intestinal inflammation in immunosuppressed rats with experimentally induced mucositis, and may protect the intestine from changes induced by chemotherapy, thus contributing to overall health.

L-carnitine has a protective effect on the colonic mucosa during abdominopelvic radiotherapy in rats

ABSTRACT PURPOSE: To evaluate histopathologically the radioprotective effect of L-carnitine on the colonic mucosa in rats undergoing abdominopelvic irradiation. METHODS: Thirty-two rats were randomly assigned to four experimental groups: intraperitoneal administration of normal saline (group 1) or L-carnitine (300 mL/kg; group 2), followed in groups 3 and 4, respectively, by one dose of abdominopelvic radiation (20 Gy) 30 min later. Rats were sacrificed 5 days after radiation, and their descending colons were resected for histopathological evaluation of the presence and severity of damage. RESULTS: Average damage scores did not differ significantly between groups 1 and 2 (0.13 ± 0.35 and 0.25 ± 0.46, respectively); the group 3 score was highest (10.25 ± 0.71), and the group 4 score (3.63 ± 1.41) was significantly lower than that of group 3 (both p = 0.0001). Pre-radiation L-carnitine administration significantly reduced mucosal thinning, crypt distortion, reactive atypia, inflammation, cryptitis, and reactive lymph-node hyperplasia (all p < 0.01). CONCLUSIONS: L-carnitine had a radioprotective effect on rat colonic mucosa. L-carnitine use should be explored for patients with gastrointestinal cancer, who have reduced serum L-carnitine levels.

Bladder carcinogenesis in rats subjected to ureterosigmoidostomy and treated with L-lysine / Carcinogênese de bexiga em ratas submetidas à ureterossigmoidostomia tratadas com L-lisina

ABSTRACT Objective: to evaluate the effect of L-lysine in the bladder and intestinal epithelia in rats submitted to vesicosigmoidostomy. Methods: we divided forty Wistar rats into four groups: group I - control group (Sham); group II - submitted to vesicosigmoidostomy and treated with L-lysine 150mg/kg; group III - submitted only to vesicosigmoidostomy; and group IV - received L-lysine 150mg/kg. After eight weeks the animals were sacrificed. Results: in the bladders of all operated animals we observed simple, papillary and nodular hyperplasia of transitional cells, transitional cell papillomas and squamous metaplasia. As for the occurrence of aberrant crypt foci in the colons of operated animals, we did not observe statistically significant differences in any of the distal, proximal and medium fragments, or in all fragments together (p=1.0000). Conclusion: Although statistically there was no promotion of carcinogenesis in the epithelia of rats treated with L-lysine in the observed time, it was clear the histogenesis of bladder carcinogenesis in its initial phase in all operated rats, this being probably associated with chronic infection and tiny bladder stones.

RESUMO Objetivo: o objetivo deste trabalho é avaliar o efeito da L-lisina nos epitélios vesical e intestinal de ratas submetidas à vesicossigmoidostomia. Métodos: quarenta ratas Wistar, foram divididas em quatro grupos: grupo I- grupo controle (Sham); grupo II- submetido à vesicossigmoidostomia e tratado com L-lisina 150mg/kg; grupo III- submetido apenas à vesicossigmoidostomia; e grupo IV- recebeu L-lisina 150mg/kg. Após oito semanas os animais foram sacrificados. Resultados: na bexiga de todos os animais operados observou-se hiperplasia simples, papilar e nodular de células transicionais, papiloma de células transicionais e metaplasia escamosa. Quanto à ocorrência de focos de criptas aberrantes nos colos dos animais operados, não foi evidenciado diferença estatística significante em nenhum dos fragmentos distal, proximal e médio, e todos juntos (P=1,0000). Conclusão: apesar de, estatisticamente, não ter havido promoção de carcinogênese nos epitélios dos ratos tratados com L-lisina, no tempo observado, é nítida a histogênese da carcinogênese de bexiga em sua fase inicial, no epitélio vesical, em todos os ratos operados, estando esta provavelmente associada à infecção crônica e aos diminutos cálculos vesicais.

ADMINISTRATION OF H2 BLOCKERS IN NSAID INDUCED GASTROPATHY IN RATS: effect on histopathological changes in gastric, hepatic and renal tissues

ABSTRACT Background Nonsteroidal anti-inflammatory drugs induces gastric mucosal lesions because of its acidic properties. Ranitidine, an H2 receptor antagonist, has proved beneficial in patients with gastric ulcers. Objective The present study was performed to assess the effect of administering ranitidine in Nonsteroidal anti-inflammatory drugs (diclofenac, nimesulide) induced gastropathy, and their effect on the histopathology of stomach, kidney and liver. Methods Diclofenac, nimesulide, and ranitidine were administered in doses of 2, 4, and 6 mg/kg, p.o. once daily for 14 days, and their effect on gastric volume, acidity, mean ulcer number, and gastric pH. In addition, histopathological examination was also performed on sections of stomach, kidney and liver. Results Following the administration of diclofenac or nimesulide, all the gastric parameters were significantly altered as well as the histopathology of stomach, liver and kidney. In the control group, the renal sections showed normal glomeruli with no thickening of glomerular basement membrane, while in diclofenac alone, nimesulide alone, and ranitidine with nimesulide groups, the thickening of glomerular basement membrane was observed. These alterations were observed to be reversed in the ranitidine with diclofenac group. In the sections from the liver, the control group showed anastomosing plates and cords of cuboidal hepatocytes with round well stained nuclei and abundant cytoplasm. In the ranitidine with diclofenac, and ranitidine with nimesulide groups, mild dilatation of sinusoids is seen coupled with prominence of central vein. In the diclofenac alone and nimesulide alone groups, the proximal and distal convoluted tubules show mild focal tubular necrosis. In the gastric sections, the control group showed several folds forming villi, and the epithelial lining surface of the mucosa. In the ranitidine with diclofenac, and ranitidine with nimesulide groups, the duodenum showed scattered inflammatory cells composed predominantly of lymphocytes. In diclofenac alone and nimesulide alone group, the sections from the gastric areas showed partial necrosis and mild chronic inflammation respectively. Conclusion The study, therefore, has provided therapeutic rationale towards simultaneous administration of H2 receptor blocker ranitidine with diclofenac to be more beneficial as compared to ranitidine with nimesulide, to minimise the gastric intolerance of diclofenac in long term treatment of inflammatory conditions.

RESUMO Contexto Anti-inflamatórios não esteroidais induzem lesões da mucosa gástrica devido às suas propriedades ácidas. Ranitidina, um antagonista dos receptores H2, revelou-se benéfico em pacientes com úlceras gástricas. Objetivo - O presente estudo foi realizado para avaliar o efeito da administração de ranitidina em gastropatia induzida por anti-inflamatórios não esteroidais (diclofenaco, nimesulida) e seu efeito sobre a histopatologia do estômago, dos rins e fígado. Métodos Diclofenaco, nimesulida e ranitidina foram administradas em doses de 2, 4 e 6 mg/kg, p.o. uma vez diariamente por 14 dias e seu efeito sobre o volume gástrico, acidez, significam o número de úlcera e o pH gástrico. Além disso, o exame histopatológico também foi realizado em seções do estômago, dos rins e fígado. Resultados Após a administração de diclofenaco ou nimesulida, todos os parâmetros gástricos foram significativamente alterados assim como a histopatologia do estômago, fígado e rim. No grupo controle, as seções renais mostraram glomérulos normais sem espessamento da membrana basal glomerular, enquanto em diclofenaco isolado, nimesulida isolado e grupos com ranitidina e nimesulida, foi observado espessamento da membrana basal glomerular. Estas alterações observou-se serem revertidas no grupo ranitidina com diclofenaco. As seções do fígado, o grupo controle mostrou placas e cordões de hepatócitos cuboidais anastomosados com núcleos bem demarcados e citoplasma abundante. Nos grupos ranitidina com diclofenaco e ranitidina com nimesulida, leve dilatação dos sinusoides é vista acoplados com proeminência de veia central. Nos grupos diclofenaco e nimesulida sozinhos, túbulos proximais e distais contorcidos mostram necrose tubular focal leve. Nas secções gástricas, o grupo controle mostrou várias dobras formando vilosidades e a superfície do revestimento epitelial da mucosa. Nos grupos ranitidina com diclofenaco e ranitidina com nimesulida, o duodeno mostrou dispersas células inflamatórias predominantemente compostas por linfócitos. Nos grupos diclofenaco e nimesulida sozinhos, as secções de áreas gástricas mostraram necrose parcial e inflamação crônica moderada respectivamente. Conclusão - O estudo, portanto, forneceu o fundamento terapêutico para administração simultânea de bloqueador de receptor H2 (ranitidina) com diclofenaco, sendo mais benéfica em comparação com ranitidina com nimesulida para minimizar a intolerância gástrica de diclofenaco no tratamento a longo prazo de condições inflamatórias.

Does Polyethylene Glycol (PEG) Plus Ascorbic Acid Induce More Mucosal Injuries than Split-Dose 4-L PEG during Bowel Preparation?

BACKGROUND/AIMS: The aims of this study were to compare the bowel-cleansing efficacy, patient affinity for the preparation solution, and mucosal injury between a split dose of poly-ethylene glycol (SD-PEG) and low-volume PEG plus ascorbic acid (LV-PEG+Asc) in outpatient scheduled colonoscopies. METHODS: Of the 319 patients, 160 were enrolled for SD-PEG, and 159 for LV-PEG+Asc. The bowel-cleansing efficacy was rated according to the Ottawa bowel preparation scale. Patient affinity for the preparation solution was assessed using a questionnaire. All mucosal injuries observed during colonoscopy were biopsied and histopathologically reviewed. RESULTS: There was no significant difference in bowel cleansing between the groups. The LV-PEG+Asc group reported better patient acceptance and preference. There were no significant differences in the incidence or characteristics of the mucosal injuries between the two groups. CONCLUSIONS: Compared with SD-PEG, LV-PEG+Asc exhibited equivalent bowel-cleansing efficacy and resulted in improved patient acceptance and preference. There was no significant difference in mucosal injury between SD-PEG and LV-PEG+Asc. Thus, the LV-PEG+Asc preparation could be used more effectively and easily for routine colonoscopies without risking significant mucosal injury.

Effect of visfatin on the structure and immune levels in the small intestine of LPS-induced rats / Efecto de la visfatina sobre la estructura y los niveles de inmunidad en el intestino delgado de ratas inducidas por lipopolisacáridos

This study investigated the effects of visfatin on the structure and the immunity levels in the small intestine of LPS-induced rats. Forty Wistar male and female SPF rats were randomly and equally divided into four groups: the saline (control), vistfatin, lipopolysaccharide (LPS), and visfatin+LPS co-stimulated. The functions of visfatin in the intestinal mucosal immunity were investigated by examining the variation of tissue structure, inflammation and immunity-related proteins in the intestine of immunologically stressed rats using HE staining, ELISA, immunohistochemistry and Western Blot. The results showed that, when compared with the control group, the visfatin-treated group showed a decrease in the intestinal villus height and width, and a significant increase in the levels of IL-6 and TNF-ð as well as Immunoglobulin A (IgA) positive cells. Additionally, when compared with the LPS-treated group, the visfatin+LPS co-stimulated group showed a decrease in the villus height and width as well as the levels of IL-6 and TNF-ð, and an increase in IgA levels, implying a shrinking response to LPS injection. All the results suggest that, under normal physiological conditions, visfatin disturbs the body's homeostasis and causes intestinal villus atrophy by increasing IgA expression. While under immune response conditions, LPS acts as an exogenous antigen to promote visfatin against LPS-induced inflammation by decreasing the expression of IgA. Under immune stress conditions, visfatin as an exogenous stimulus promotes the immune response by regulating the protein levels of IL-6, TNF-ð and IgA.

Este estudio investigó los efectos de la visfatina sobre la estructura y los niveles de inmunidad en el intestino delgado de ratas inducidas por lipopolisacáridos (LPS). Cuarenta ratas Wistar se dividieron aleatoriamente e igualmente en cuatro grupos: solución salina (control), vistafin, LPS y visfatina + LPS co-estimuladas. Las funciones de la visfatina en la inmunidad de la mucosa intestinal se investigaron mediante el examen de variación de la estructura del tejido, la inflamación y las proteínas relacionadas con la inmunidad en el intestino de ratas estresadas inmunológicamente; usando tinción HE, ELISA, inmunohistoquímica y Western Blot. Los resultados mostraron que, en comparación con el grupo control, el grupo tratado con visfatina presentó una disminución en la altura y ancho de las vellosidades intestinales, y un aumento significativo en los niveles de IL-6 y TNF-ð, así como inmunoglobulina A (IgA células positivas). Además, al comparar este grupo con el grupo tratado con LPS- el grupo visfatina + LPS co-estimulado mostró una disminución en la altura y ancho de las vellosidades, así como en los niveles de IL-6 y TNF-ð, y un aumento en los niveles de IgA, lo que implica reducción de una respuesta a la inyección LPS. Todos los resultados sugieren que, en condiciones fisiológicas normales, la visfatina perturba la homeostasis del cuerpo y provoca la atrofia de las vellosidades intestinales mediante el aumento de la expresión de IgA. Mientras que bajo condiciones de la respuesta inmune, LPS actúa como un antígeno exógeno para promover visfatina contra la inflamación inducida por LPS por la disminución de la expresión de IgA. En condiciones de estrés inmunológico, la visfatina como estímulo exógeno promueve la respuesta inmune mediante la regulación de los niveles de proteína de IL-6, TNF-ð e IgA.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/-) and wild-type (APOE+/+) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

Tissue content of sulfomucins and sialomucins in the colonic mucosa, without fecal stream, undergoing daily intervention with sucralfate

PURPOSE: To measure the content of acidic mucin, sialomucin, and sulfomucins in the colonic mucosa without fecal stream submit to intervention with sucralfate (SCF). METHODS: Thirty-six rats were submitted to a right colostomy and a distal mucous fistula and divided into two groups according to sacrifice to be performed two or four weeks. Each group was divided into three subgroups according daily application of enemas containing saline, SCF at 1.0 g/kg/day or 2.0 g/kg/day. Colitis was diagnosed by histological analysis. Acid mucins were determined with the Alcian-Blue and sulfomucin and sialomucin by high iron diamine-alcian blue (HID-AB) techniques. The mucins were quantified by computer-assisted image analysis. Mann-Whitney and ANOVA tests were used to analyze the results establishing the level of significance of 5% for both (p<0.05). RESULTS: SCF enemas decreased the inflammation score and was related to the concentration used and time of the intervention. SCF at both concentrations increased the content of acid mucin, which was related to the concentration used and to the improvement in the inflammatory score. There was an increase in the content of sulfomucins and sialomucins in SCF groups. SCF increased sulfomucins from 2 weeks of intervention, which was not related to the dose or time of application. The increase in sialomucin content was related to the time and dose used in the intervention. CONCLUSION: Sucralfate increased the content of acidic mucins, primarily at the expense of sialomucin, which was affected by the dose and time of intervention. .