Abnormalities of digestive tract innervation in rat fetus treated with ethylenethiourea / Anomalias da inervação do trato digestório de fetos de ratas expostas à etilenotioureia

PURPOSE: The pathophysiology of abnormalities associated with myenteric plexus lesions remains imperfectly understood. Such abnormalities have been correlated with subocclusive intestinal conditions in children with Hirschsprung's disease, cases of chronic constipation and, postoperatively, in cases of anorectal anomalies. This study evaluated abnormalities of the myenteric plexus in fetus from female rats that received ethylenethiourea. METHODS: Female rats were exposed to ethylenethiourea on the 11th day of pregnancy (experimental group) or to 0.9 percent physiological solution (control group). Abnormalities were only found in the experimental group. The digestive tract muscle layer was analyzed morphometrically and changes to the frequencies of nerve plexus cells and interstitial cells of Cajal were evaluated, using hematoxylin-eosin, S-100 protein, neuron-specific enolase and C-Kit, respectively. RESULTS: Muscle and skeletal abnormalities were observed in 100 percent, anorectal anomalies in 86 percent, absent tail in 71 percent, short tail in 29 percent, duodenal atresia in 5 percent, esophageal atresia in 5 percent and persistent omphalomesenteric duct in 5 percent. Histopathological analysis showed a thinner muscle layer associated with lower frequencies of ganglion cells and interstitial cells of Cajal, in all gastrointestinal tract. CONCLUSION: Severe nerve plexus abnormalities associated with muscle layer atrophy were observed throughout the gastrointestinal tract in newborn rats exposed to ethylenethiourea.

OBJETIVO: As anomalias associadas a lesões dos plexos mioentéricos permanecem sem plena compreensão da sua fisiopatologia. Alterações nos plexos nervosos têm sido correlacionadas com quadros suboclusivos intestinais em crianças portadoras de doença de Hirschsprung, em constipação crônica e no pós-operatório de anomalias anorretais. Este estudo avaliou as anomalias do plexo mioentérico em fetos de ratos fêmea que ingeriram etilenotioureia (ETU). MÉTODOS: Ratos fêmea foram expostos no 11º dia de gestação a ETU 1 por cento no Grupo Experimento e a solução fisiológica 0,9 por cento no Grupo Controle. Foram observadas anomalias apenas no Grupo experimento, sendo realizada morfometria da camada muscular e avaliadas alterações da frequência celular nos gânglios do plexo mioentérico e nas células intersticiais de Cajal (CIC) utilizando hematoxilina-eosina, P S-100, Enolase Neurônio Específica e C-KIT. RESULTADOS: Foram observadas anomalias musculoesqueléticas (100 por cento), anorretais (86 por cento), ausência de cauda (71 por cento), cauda curta (29 por cento), atresia duodenal (5 por cento), atresia esofágica (5 por cento) e conduto onfalomesentérico persistente (5 por cento). A análise histopatológica mostrou adelgaçamento da camada muscular associada às alterações da frequência das células ganglionares e das CIC em todos os segmentos do trato gastrointestinal. CONCLUSÃO: Foram observadas alterações graves nos plexos nervosos associadas ao adelgaçamento da camada muscular de todo o trato gastrointestinal nos fetos expostos a ETU.

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.