Stress-induced Alterations in Mast Cell Numbers and Proteinase-activated Receptor-2 Expression of the Colon: Role of Corticotrophin-releasing Factor

This study was performed in order to assess whether acute stress can increase mast cell and enterochromaffin (EC) cell numbers, and proteinase-activated receptor-2 (PAR2) expression in the rat colon. In addition, we aimed to investigate the involvement of corticotrophin-releasing factor in these stress-related alterations. Eighteen adult rats were divided into 3 experimental groups: 1) a saline-pretreated non-stressed group, 2) a saline-pretreated stressed group, and 3) an astressin-pretreated stressed group. The numbers of mast cells, EC cells, and PAR2-positive cells were counted in 6 high power fields. In proximal colonic segments, mast cell numbers of stressed rats tended to be higher than those of non-stressed rats, and their PAR2-positive cell numbers were significantly higher than those of non-stressed rats. In distal colonic segments, mast cell numbers and PAR2-positive cell numbers of stressed rats were significantly higher than those of non-stressed rats. Mast cell and PAR2-positive cell numbers of astressin-pretreated stressed rats were significantly lower than those of saline-pretreated stressed rats. EC cell numbers did not differ among the three experimental groups. Acute stress in rats increases mast cell numbers and mucosal PAR2 expression in the colon. These stress-related alterations seem to be mediated by release of corticotrophin-releasing factor.

Increased Immunoendocrine Cells in Intestinal Mucosa of Postinfectious Irritable Bowel Syndrome Patients 3 Years after Acute Shigella Infection: An Observation in a Small Case Control Study

PURPOSE: Postinfectiously irritable bowel syndrome (PI-IBS) develops in 3-30% of individuals with bacterial gastroenteritis. Recent studies demonstrated increases in inflammatory components in gut mucosa of PI-IBS patients even after complete resolution of infection. We aimed to investigate histological changes in colon and rectum of PI-IBS subjects after long term period of infection. MATERIALS AND METHODS: We recruited PI-IBS subjects who had been diagnosed IBS after complete resolution of enteritis caused by shigellosis outbreak 3 years earlier. We compared unmatched four groups, PI-IBS (n = 4), non PI-IBS (n = 7), D-IBS (n = 7, diarrhea predominant type) and healthy controls (n = 10). All of them underwent colonoscopic biopsy at three areas, including descending colon (DC), sigmoid colon (SC) and rectum, which were assessed for 5-hydroxytryptamine (5-HT)/peptide YY (PYY)-containing enterochromaffin (EC) cell, intraepithelial (IEL) and lamina propria T lymphocyte (CD3), CD8 lymphocytes, mast cells and CD68/calprotectin+ macrophages. RESULTS: All subjects had no structural or gross abnormalities at colonoscopy. In PI-IBS, 5-HT containing EC cells, PYY containing EC cells, IELs, CD3 lymphocytes, CD8 lymphocytes, mast cells, and CD68 + macrophages were increased compared to control (p < 0.05). In D-IBS, PYY containing EC cells, IELs, and CD3 lymphocytes were increased compared to control (p < 0.05). In PI-IBS, 5-HT containing EC cells tended to increase and PYY containing EC cells, CD8 lymphocytes, mast cells, and CD68+ macrophages were increased compared to non PI-IBS (p < 0.05). Calprotectin + marcrophages were decreased in PI-IBS, non PI-IBS and IBS compared to control. CONCLUSION: The immunoendocrine cells were sporadically increased in PI-IBS, non PI-IBS and D-IBS compared with control. Our findings in a very small number of patients suggest that mucosal inflammation may play a role in long-term PI-IBS, and that other sub-groups of IBS and larger scale studies are needed to confirm this observation.

Quantificaçäo e distribuiçäo de células argirófilas e argentafins no estômago de suínos com e sem úlcera gástrica / Quantification and distribution of argirophils and argentafins cells in swine stomach with and without gastric ulcer

Com a finalidade de se conhecer a distribuiçäo e o número das células endócrinas do estômago de suínos com e sem úlcera gástrica da pars oesophagea procedeu-se ao presente trabalho. Os estômagos de 32 suínos adultos, com mucosa gástrica macroscopicamente normal e de outros 32 com úlcera gástrica da pars oesophagea, foram colhidos após o abate. Fragmentos de regiöes padronizadas da mucosa antral (n=2), mucosa oxíntica (n=2) e cárdica (n=2) foram fixados em Bouin e incluídos em parafina. Células argirófilas e argentafins foram demonstradas pelos métodos de Grimelius e Masson-Fontana, respectivamente, quantificadas e analisadas quanto à distribuiçäo nos diferentes tipos de mucosa. Nos animais estudados as células argirófilas foram mais frequentes na mucosa oxíntica, em relaçäo às mucosas antral e cárdica. Por sua vez, as células argentafins foram mais frequentes na mucosa antral do que na mucosa oxíntica (P<0,05). Näo ocorreram diferenças quanto a distribuiçäo e quanto ao número de células argirófilas e argentafins entre os dois grupos de animais estudados, com e sem úlcera gástrica.

Effect of cerebellar modulation on rat gastric secretion and enterochromaffin-like cell.

Effect of cerebellar lesion and vestibular stimulation (VS) on the activity and alternation of ECL-cells along with changes in gastric volume and acid secretion was studied. The results suggest that cerebellar lesion caused increased gastric volume and acid secretion and tended to decrease ECL-cell density. On the other hand VS of nodular lesioned rats resulted in decrease of above parameter which became marked only after 21 days of nodular lesion.

Células endócrinas gastrointestinais: breve histórico e principais métodos de identificaçäo à microscopia óptica / Gastrointestinal endocrine cells: brief history and main identification methods under light microscopy

O trato gastrointestinal apresenta um amplo espectro de células endócrinas distribuídas difusamente ao longo da mucosa, intercaladas com as células exócrinas. Essas células compartilham diversas características como a capacidade de produzir vários peptídios. Apesar do grande desenvolvimento da endocrinologia digestiva, especialmente na última década e no que tange ao conhecimento bioquímica e localizaçao celular dos peptídios reguladores gastrointestinais, seu significado funcional e papel na fisiopatologia digestiva permanecem em parte desconhecidos. É apresentado um resumo das principais informaçoes sobre características morfológicas, histoquímicas, origem embriológica, dados históricos e métodos de identificaçao das células endócrinas do trato gastrointestinal.