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.

Phenotypic changes of interstitial cells of Cajal after intestinal obstruction in rat model

The objective was to study the effect of mechanical intestinal obstruction in rats on the phenotype of interstitial cells of Cajal (ICC). Healthy Wistar rats were randomly divided into sham-operation group (C), one day obstruction group (M1), two days obstruction group (M2), and three days obstruction group (M3), with 10 rats in each group. The expression of SCF mRNA and c-Kit protein in intestinal tissue was investigated by RT-PCR and immunohistochemistry. Compared with the sham-operation group, the relative expression of SCF mRNA and the expression of c-Kit protein in intestinal tissue were significantly decreased in both obstruction groups. Levels decreased gradually with the prolongation of obstruction time, and significantly decreased on the 3rd day after obstruction (P<0.05). Immunohistochemical staining of the small intestine showed that the number of ICC in the sham-operation group was the highest, and they were gradually decreased with the extension of obstruction time in the M1 to M3 groups. There was a significant difference between groups (P<0.05). Intestinal obstruction caused a decrease in the concentrations of SCF mRNA and c-Kit protein in ICC. With the prolongation of intestinal obstruction, the number of ICCs gradually decreased.

Effect of bisacodyl on rats with slow transit constipation

The effect of bisacodyl on the treatment of rats with slow transit constipation (STC) was studied. Forty-five female Wister rats were divided into control group, STC group, and STC bisacodyl group. The immunohistochemical method was used to determine interstitial cells of Cajal (ICC) and the expression of c-Kit protein. Body mass and the number of defecations were significantly decreased in the STC group compared with the control group on the 100th day after diphenoxylate administration, while dry weight of feces was significantly increased and the intestinal transit time was prolonged. There were significant differences in the number of defecations, dry weight of feces, and intestinal transit time among the three groups. The number of defecations was higher, dry weight of feces was lower, and intestinal transit time was shorter in the STC bisacodyl group compared to the STC group. In addition, ICC basement membrane dissolution occurred in the colon wall of the STC group. The connection between ICC and surrounding cells was destroyed, and the nucleus shrunken to different degrees. Moreover, c-Kit expression in the STC group was significantly lower than the control group. The connection between ICC and surrounding cells in the STC bisacodyl group was significantly stronger than the STC group, and the number of ICC and the expression of c-Kit were increased. Bisacodyl could reduce the severity of STC in rats by increasing the number of ICC and the expression of c-Kit.

Interstitial cells of cajal in normal human alimentary tract: an immunohistochemical study

Objectiver lnterstitial cells of Cajal [ICC] are c-kit positive immunoreactive cells which are thought to play an important role in the control of gut motility. The work aimed at studying the morphology of ICC and precisely localize their regional and transmural pattern of distribution in normal human alimentary tract. The study included 102 normal human alimentary tract specimens obtained from male patients with a mean age 37.92 +/- 8.53. All sections were stained with hematoxylin and eosin and c-kit immunohistochemical staining. Immunohistochemically stained sections were submitted for a computer aided image analytical study to detect the area percent of immunoreactive cells. The data obtained was statistically analyzed. ICC could not be demonstrated in H and E stained sections. Immunohistochemically, two morphological subtypes of ICC were recognized, a spindle bipolar and stellate multipolar forms. ICC were detected in the myenteric plexus layer of the esophagus, corpus, pylorus, small intestine, colon and rectum. Intramuscular ICC could be demonstrated in the esophagus, fundus, corpus, pylorus, colon, rectum and anal canal. ICC at the deep muscular plexus were found only in the small intestine. In the pylorus, colon and rectum, ICC were also found at the submucosal border of the circular muscle layer. The wide distribution of ICC all over the human alimentary tract is compatible with their physiological role being important mediators of gut motility

Interstitial cells of Cajal and intestinal function in Trinidadian children / Células intersticiales de Cajal y función intestinal en niños trinitenses

OBJECTIVE: This study was carried out to compare the density of the interstitial cells of Cajal (ICCs) in the bowel wall of children with Hirschsprung's disease (HD), anorectal malformations (ARM) and normal controls in Trinidad and Tobago. SUBJECTS AND METHOD: Segments of bowel wall excised from eight children with HD, three controls and two children with ARM were immunostained with c-Kit primary antibody. Cells with features of ICCs were counted. RESULTS: All three controls and the two children with ARM had dense distribution of ICCs. Most children (6/8;75%) with HD had markedly reduced counts in aganglionic bowel. Two (25%) also had a decrease in ganglionic bowel. Possible influences were patient age and gender and the level of bowel sectioned. CONCLUSION: Analysis of this sample suggests that immunostaining for c-Kit positive cells might be a useful screening test in the assessment of bowel motility disorders. The possible effects of age, gender and the level of bowel sampled await determination.

OBJETIVO: Este estudio se llevó a cabo con el propósito de comparar la densidad de las células intersticiales de Cajal (CIC) en las paredes intestinales de niños con la enfermedad de Hirschprung (EH), y malformaciones anorectales (MAR), frente a controles normales en Trinidad Tobago. SUJETOS Y MÉTODOS: Segmentos de las paredes intestinales les fueron extirpados a ocho niños con EH; tres controles y dos niños con MAR fueron inmunoteñidos con anticuerpo primario c-kit. Se contaron las células con características de CIC. RESULTADOS: Los tres controles y los dos niños con MAR presentaban una distribución densa de CICs. La mayor parte de los niños (6/8; 75%) con EH tuvieron conteos marcadamente reducidos de intestino agangliónico. Dos niños (25%) también tuvieron una disminución de intestino gangliónico. Entre las influencias posibles se cuentan la edad y el género del paciente así como el nivel de intestino seccionado. CONCLUSIÓN: El análisis de esta muestra sugiere que la inmunotinción para células c-kit positivas podría ser un útil test de pesquisaje a la hora de evaluar desórdenes en la motilidad intestinal. Los efectos posibles de la edad, el género y el nivel de intestino muestreado, están pendientes de determinación.