Tissue quantification of neutral and acid mucins in the mucosa of the colon with and without fecal stream in rats

Abstract

Purpose:To quantify the intensity of the expression of neutral and acids mucins in mucosa of the colon with and without fecal stream and to correlate this with the duration of fecal transit diversion. Methods: Thirty male Wistar rats were subjected to fecal transit deviation in the left colon by a proximal colostomy and a distal mucous fistula. The animals were divided into three experimental groups, according to whether sacrificing would be performed six, 12 or 18 weeks after surgery. The expression of neutral and acid mucins was evaluated using the histochemical techniques of Periodic Acid Schiff and Alcian Blue, respectively. The tissue mucins expression was quantified by computer-assisted image analysis software (NIS-Elements) in the segments with and without fecal stream. Student's paired t test was used to compare the quantities of mucins in colon with or without fecal stream and variance between the experimental groups by ANOVA and Newman-Keuls post-test, establishing level of signification of 5% (p<0.05). Results: There were significant decreased quantities of acid and neutral mucins in the colon without transit, compared with the colon with fecal stream, independent of the duration of exclusion. There was increased expression of neutral mucins in the colon with fecal stream after 12 and 18 weeks of exclusion. There was no increase in the expression of acid mucins in the colon with transit as the duration of fecal transit exclusion progressed. There was increased production of acid mucins in the animals submitted to diversion of the fecal stream for 18 weeks, compared with those subjected to diversion for 6 and 12 weeks. In the colon without fecal stream, there was increased expression of neutral mucins after 12 and 18 weeks of exclusion. Conclusions: Deviation of the fecal stream decreased the expression of acid and neutral mucins in the segments without fecal transit, compared with segments with transit. Regardless of the reduced expression of acid and neutral mucins in the segments without fecal stream, their tissue expression increased with increasing duration of intestinal deviation. Key words: Colitis. Colostomy. Mucins. Sialomucins. Image Processing, Computer-Assisted. RESUMOObjetivo: Quantificar a intensidade de expressão de mucinas neutras e ácidas na mucosa cólica provida e desprovida de trânsito intestinal relacionando-a ao tempo de exclusão fecal. Métodos: Trinta ratos Wistar machos foram submetidos à derivação do trânsito no cólon esquerdo por colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo o sacrifício ter sido realizado seis, 12 e 18 semanas após a cirurgia. A avaliação da expressão de mucinas neutras e ácidas na mucosa cólica foi realizada com as técnicas histoquímicas do Periódico Ácido de Schiff e Azul de Alcian, respectivamente. A quantificação da expressão tecidual das mucinas foi com auxílio de programa de análise de imagem assistida por computador (NIS-Elements) nos segmentos providos e desprovidos de trânsito fec...

Evaluation of the application of enemas containing sucralfate in tissue content of neutral and acid mucins in experimental model of diversion colitis

“…The authors found that although there is a reduction in both types of mucins the reduction of the tissue content of acidic mucins was more important 13 . Subsequently, the same group studying …”

“…Previous studies have shown that there is significant reduction in the content of neutral and acidic mucins in the mucosa devoid of the fecal stream 13 . The authors found that although there is a reduction in both types of mucins the reduction of the tissue content of acidic mucins was more important 13 .…”

“…The capacity of the colonic epithelium to produce mucins depends on adequate supply of SCFAs 7 . Recent studies have shown the importance of maintaining the supply of SCFAs, particularly butyrate, in order to have adequate gene expression relating to mucin formation and content of the glycoprotein 4,5,8,13 .…”

“…Despite the histopathological similarities between UC and DC, few studies has evaluated the modifications in the tissue contents and pattern of expression of neutral and acid mucins on glands of the colonic mucosa without fecal stream 4,5,13 . The results of these studies showed that the deviation of the fecal stream reduce the content and modify the pattern of tissue expression of neutral and acid mucins.…”

“…The results of these studies showed that the deviation of the fecal stream reduce the content and modify the pattern of tissue expression of neutral and acid mucins. In other words, the deficiency in the supply of SCFAs can modify the mucus that overlying the colonic mucosa, reducing the effectiveness of this first line of defense against luminal aggression 5,13 .…”