Histological, biochemical and pharmacologycal characterization of the gastric muscular layer in Chagas disease / Caracterização histológica, bioquímica e farmacológica da musculatura gástrica na doença de Chagas

PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3x1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men) submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men) submitted to other types of surgery (control group), aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6) and control (7,3) groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32) compared to the controls (7,30). No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.

OBJETIVO: Avaliar in vitro a correlação entre o número de neurônios e a sensibilidade a drogas colinérgicas e a atividade da acetilcolinesterase em pacientes chagásicos. MÉTODOS: Em 10 pacientes chagásicos crônicos (6 homens) submetidos à cirurgia de megaesôfago ou de megacólon e em 10 pacientes não chagásicos (4 homens) submetidos a outros tipos de cirurgia (grupo controle), respectivamente com idade média de 52,3 e 50,1 anos, retirou-se uma tira de 3x1 cm da camada muscular da parede anterior do estômago, sempre junto á cisura angular, que serviu para os estudos histológicos e farmacológicos. A ação de drogas colinérgicas foi feita em preparação isolada de acordo com o método de superfusão de Ferreira e Costa, e a determinação da atividade da acetilcolinesterase pelo método de Ellman. Para a contagem de neurônios a tira muscular foi submetida a cortes de 8 micra segundo método padronizado por Alcântara. RESULTADOS: Houve diferença do número de neurônios entre os grupos chagásico (5,6) e controle (7,3). A atividade da acetilcolinesterase mostrou-se diminuída nos chagásicos (4,32) expressa como número de moles do substrato hidrolisado por minuto por grama de tecido, em relação aos controles (7,30). Não se encontrou hipersensibilidade da musculatura gástrica a drogas colinérgicas, encontrando-se inclusive efeito máximo reduzido ao carbacol e betanecol no grupo chagásico. CONCLUSÕES: A redução de neurônios no plexo mioentérico do estômago de pacientes chagásicos crônicos pode ser demonstrada mesmo na ausência de gastropatia chagásica clínica. A hipersensibilidade da musculatura gástrica a drogas colinérgicas provavelmente depende de desnervação intensa. A redução da atividade da acetilcolinesterase demonstra o comprometimento da inervação colinérgica no estômago de pacientes chagásicos crônicos. Não houve correlação entre número de neurônios, sensibilidade a drogas colinérgicas e atividade da acetilcolinesterase na musculatura gástrica de pacientes chagásicos ou não chagásicos.

Effects of the partial gastrectomy associated to anterior truncal vagotomy in the metabolism of the iron in rats / Efeitos da gastrectomia parcial e vagotomia troncular anterior no metabolismo de ferro de ratos

PURPOSE: To evaluate the effects of the partial gastrectomy associated to anterior truncal vagotomy in the absorption and metabolism of iron. METHODS: Eighteen adults male Wistar rats were submitted to the partial gastrectomy associated to anterior truncal vagotomy (eight animals) and the sham operation (10 animals, control group). The diet consumption and the weight gains of the animals were monitored three times during the week. The animals received supplements of vitamin B12, for the prevention of the megaloblastic anemia, and a formulated experimental diet orally and denominated AIN-93M by 8 weeks. The fecal iron, apparent absorption of the iron, haematocrit, haemoglobin and serum iron were measured after 60 days. RESULTS: The animals undergoing sham operation presented larger statistical averages (p<0.05) for the diet consumption, weight gains, apparent absorption of iron, haematocrit, haemoglobin and serum iron compared to the gastrectomized group. However, the excretion of iron in feces was larger in the gastrectomized group (+14.3 percent) (p<0.05) when compared to the control group. CONCLUSION: Partial gastrectomy associated to anterior truncal vagotomy showed to be a good experimental model the study of iron metabolism, decreasing the haematocrit, the haemoglobin and the iron absorption, consequently causing anemia.

OBJETIVO: Avaliar os efeitos da gastrectomia parcial associada a vagotomia troncular anterior na absorção e metabolismo do ferro. MÉTODOS: Dezoito ratos Wistar machos e adultos foram submetidos a gastrectomia parcial e vagotomia troncular anterior (oito animais) e à laparotomia simples como grupo controle (10 animais). O consumo de dieta e o peso dos animais foram monitorados três vezes por semana. Os animais receberam suplementos de vitamina B12 para prevenção de anemia megaloblástica, além de dieta oral formulada experimentalmente e denominada AIN-93M, durante 8 semanas. O ferro fecal, a absorção aparente de ferro, o hematócrito a hemoglobina e o ferro sérico foram mensurados, após 60 dias de observação. RESULTADOS: Os animais controles apresentaram médias estatísticas maiores (p <0.05) para o consumo de dieta, ganho de peso, absorção aparente de ferro, hematócrito, hemoglobina e ferro sérico comparados aos animais gastrectomizados. Entretanto, a excreção de ferro nas fezes foi superior no grupo de animais gastrectomizados (+14.3 por cento) (p<0.05) quando comparado com o grupo controle. CONCLUSÃO: A gastrectomia parcial associada a vagotomia troncular anterior mostrou ser um bom modelo experimental para o estudo do metabolismo do ferro, ocasionando diminuição do hematócrito, da hemoglobina e absorção de ferro, e conseqüentemente causando anemia.

Obesity and Gastrointestinal Motility / 대한소화기학회지

Gastrointestinal (GI) motility has a crucial role in the food consumption, digestion and absorption, and also controls the appetite and satiety. In obese patients, various alterations of GI motility have been investigated. The prevalence of GERD and esophageal motor disorders in obese patients are higher than those of general population. Gastric emptying of solid food is generally accelerated and fasting gastric volume especially in distal stomach is larger in obese patients without change in accommodation. Contractile activity of small intestine in fasting period is more prominent, but orocecal transit is delayed. Autonomic dysfunction is frequently demonstrated in obese patients. These findings correspond with increased appetite and delayed satiety in obese patients, but causes or results have not been confirmed. Therapeutic interventions of these altered GI motility have been developed using botulinum toxin, gastric electrical stimulation in obese patients. Novel agents targeted for GI hormone modulation (such as ghrelin and leptin) need to be developed in the near future.

Immunohistochemical localization of calcium binding proteins and some neurotransmitters in myenteric plexus of goat stomach

To understand the neurochemical properties of the gastric myenteric plexus of ruminants, the expression patterns of calbindin D-28k (CB), calretinin (CR), substance P (SP) and calcitonin gene-related peptide (CGRP) were explored in the Korean native goat. In gastric myenteric plexus, CB and SP immunoreactivity were observed in round- or ovalshaped neurons. CR and CGRP immunoreactivity were detected only in the nerve fibers. This immunohistochemical localization of CB, CR, CGRP and SP in the myenteric plexus of the goat stomach exhibited species-specific patterns. These findings suggest that these substances may be directly or indirectly related to the gastric functions of the goat stomach.

Evidence of collateralization of vagal efferents innervating subdiaphragmatic segments of the gastrointestinal tract in the rat using the double labelling fluorescent dyes technique

Collateralization of the abdominal vagal trunks was investigated in the rat using double labelling fluorescence dye technique. A total of 20 adult male and female rats were used for the study. The anterior and posterior walls of the corpus and fundus of the stomach were injected with 0.1 microliter (microliter) of 5 aqueous solution of diamidino yellow (Dy) in eight rats. The same quantity and percentage of fast blue (Fb) was injected into the walls of the duodenum and proximal jejunum in the same eight rats that were injected with Dy. The anterior and posterior walls of the stomach of four rats were injected with 0.1 microliter of 5 Dy only while four other rats had injections of 0.1 microliter of Fb only into the duodenum and proximal jejunum. Two control rats had stomach injections with normal saline, and two rats had saline injections into the intestine. Each rat was perfused with a preservative 14 days after injection and serial sections taken for examination with a fluorescence microscope. The results of the experiment revealed that in the eight rats injected simultaneously with Dy and Fb, some neurons of the dorsal motor nucleus of the vagus nerve (DMX) were labelled with Dy only, some with Fb only and some were doubly labelled with Dy and Fb. No double-labelled neurons were seen in the rat injected with one dye only and no labellings at all were seen in the controls. The pattern of labelling obtained in the study is suggestive of collateralization of axons of the abdominal vagal trunks

Effect of erythromycin and cisapride on emptying of the vagally denervated intrathoracic stomach.

BACKGROUND: Subsequent to esophagectomy and reconstruction among patients with esophageal cancers, the intrathoracic denervated stomach acts as a passive conduit without peristalsis. OBJECTIVE: The study was designed to assess the impact of two prokinetic drugs viz. erythromycin and cisapride on the emptying of vagally denervated intrathoracic stomach. METHODS: Twenty consecutive patients of carcinoma esophagus, who had undergone one stage transhiatal oesophagectomy with cervical esophagogastrostomy and were disease free at three months postoperative follow-up, were included in the study. These patients were randomised into two groups of ten each. The patients in group A received erythromycin, while patients in group B received cisapride. The gastric emptying was studied by scintigraphy, using a standard test meal containing 99m Tc sulphur colloid labelled 'IDLIS' [rice based radio labelled food] before and after the drug treatment. RESULTS: The pre and post treatment mean gastric half emptying time of the patients in the erythromycin group was 52.6 min and 49.7 min (p > 0.1) and in cisapride group it was 53.76 and 26.4 min respectively (p < 0.05). Intergroup comparison of the difference was not statistically significant. CONCLUSION: Cisapride is an effective prokinetic agent in the treatment of gastric stasis of the vagally denervated intrathoracic stomach.

NADH diaphorase positive myenteric neurons of the aglandular region of the stomach of rats subjected to desnutrition

El estómago realiza movimientos caracterizados por potentes ondas peristálticas lentas, útiles en la mezcla del bolo alimenticio, la digestión mecánica y su lenta liberación por el píloro. El control de este movimiento se realiza por acción hormonal y por actividad nerviosa, destacando la inervación intrísica que representan las neuronas del plexo miotérico. Considerando que un estado de desnutrición puede provocar alteraciones morfológicas, incluso neuronas, se ha propuesto este trabajo, con el objetivo de verificar los efectos provocados por la desnutrición proteínica durante el período de 120 días, en el aspecto cuantiativo de las neuronas NADH-diaforasa positivas. Para este estudio se utilizaron 10 ratones adultos, los cuales, a los 90 días de vida fueron divididos en dos grupos; control y desnutridos. A los ratones del grupo desnutridos (n=5) se les alimentó con una dieta proteínica de, aproximadamente, 8 por ciento y a los ratones del grupo control (n=5) con dieta de valor proteínico normal, 22 por ciento. Transcurridos 120 días, al estómago aglandular se le hizo un ensayo de histoenzimología del NADH-diaforasa, para verificar características neuronales. La región glandular fue dividida en dos áreas: una proxima al lóbulo gástrico mayor y la otra, anterior al repliegue límite. En el recuento por muestreo, las neuronas observadas en 40 campos microscópicos (6,64mm²) de cada área, de las muestas de los ratones de los grupos control y desnutridos, fueron contadas con un microscopio de 40x. Constatamos entonces que las neuronas pueden estar aisladas o agrupadas en sus ganglios. Cerca del repliegue límite encontramos un promedio de 570,8 neuronas en el grupo control y 718,4 en el grupo desnutridos. Por otra parte, cerca del lóbulo gástrico mayor, encontramos 25,8 neuronas en el grupo control y 52,6 en el grupo desnutridos. La dieta hipoproteínica implicó un menor crecimiento físico, con una descompensación de alrededor de 30,33 por ciento, al compararlo con ratones del grupo control, como también hubo una reducción de la superficie del perfil estomacal, de aproximadamente 20.13 por ciento. Concluimos que, las neuronas no están distribuidas uniformemente en la pared estomacal y que en los ratones desnutridos presentaron una menor dispersión, presentando por lo tanto una mayor densidad neuronal por mm²

Investigación y revisión conceptual de la inervación gastro-duodeno-pancreática en ratas / Investigation and conceptual revision of the gastro-duodeno-pancreatic innervation in rats

En la disección anatómica macroscópica de la inervación gastro-duodeno-pancreática ratas, es posible resaltar: Una estructura conectivo-nerviosa que vincula la unión antro-fúndica con el píloro, la banda diagonal antral (BDA); dos láminas que, como telones superpuestos, cubren el espacio entre el hígado, duodeno, estómago y esófago; la más superficial de ésta, es la hépato-gastro-duodenal (HGD) y la subyacente o profunda, es la pre-post-esófago-gástrica (P-PEG). Por su riqueza neuronal, se describen dos centros autonómicos, el antro-fúndico y el peri-vateriano, este último considerado como la región más sensible del gatillo pancreático. Además, se describe en la cara anterior del colédoco, un nódulo plexual precoledociano, verdadero entrecruzamiento o carrefour de fibras nerviosas de diversas fuentes. Respecto de los nervios vagos, el izquierdo o anterior comanda la cara anterior del estómago, el segmento supra-Vateriano del duodeno y la cabeza del páncreas. Mientras, el vago derecho o posterior rige la cara posterior del estómago y el segmento córporo-caudal del páncreas. Finalmente, los carriles de la pista plexual entérica (en las paredes gástrica y duodenal) y las fibras nerviosas que saltan la hendidura duodeno-pancreática constituyen la vía de transmisión de impulsos nerviosos hacia y desde el páncreas

Quantitative study of the myenteric plexus of the stomach of rats with streptozotocin-induced diabetes

The purpose of the present study was to investigate the morphological and quantitative alterations of the myenteric plexus neurons of the stomach of rats with streptozotocin-induced chronic diabetes and compare them to those of non-diabetic animals. Samples from the body of the stomach were used for whole-mount preparations stained with NADH-diaphorase and for histological sections stained with hematoxylin-eosin. It was observed that diabetes cause a significant decrease on the number of neurons

Neural hypertrophy in carcinoma stomach.

Neural hypertrophy with hyperplastic Schwann cells in the wall of the stomach along with enterochromaffin cell hyperplasia was incidentally observed at histology in the gastrectomy specimen of a 43-year-old man with carcinoma stomach who had presented with upper abdominal pain of one year duration. The patient had no previous abdominal surgery or evidence of gastrointestinal obstructive pathology. The significance of this neural hypertrophy is not known.

Sprouting of the vagus nerve after highly selective vagotomy: an autoradiographic study in the ferret stomach

In this study, the sprouting of the vagal nerve terminals were investigated in the ferret stomach after highly selective vagotomy by using the autoradiographic technique. The acute experimental animals which had highly selective vagotomy were injected immediately with tritiated leucine into the vagal dorsal motor nucleus. autoradiographic examination of the body of the stomach failed to show any labelled nerve fibres, while the pylorus showed many labelled nerve fibers. These observations indicate that the highly selective vagotomy has been performed successfully. Abdominal examination, of the chronic experimental animals, three months after highly selective vagotomy. bridges of scar tissue were observed by passing the vagotomy ligatures to supply the stomach. Histological examination of the regrown tissue showed that it was normal nerve fibres. After cutting this regrown tissue and injection of these chronic animals with tritiated leucine into the vagal dorsal motor nucleus, labelled nerve fibres were seen in the body of the stomach. This indicates that terminals reactive sprouting of the vagus nerve has spread from the pylorus to supply the body of the stomach. This phenomenon of the compensatory reactive sprouting of the vagal nerve terminals may explain the recovery of gastric function and may account for the failures of highly selective vagotomy in humans. However, modification of surgery may decrease the high rate of incidence of recurrent peptic ulcer after highly selective vagotomy

The effect of bilateral gastric vagotomy and histamine stimulation on parietal cell activity in streptozotocin induced diabetic rat model.

Disturbances in gastric secretions are commonly associated with diabetes mellitus and are usually attributed to autonomic neuropathy. Systematic documentation of the effects of experimental diabetes on parietal cell functions are not available. This study has been designed to evaluate the acid secretory status of the parietal cells in streptozotocin (STZ) induced rat model of diabetes mellitus by assessing the effect of bilateral gastric vagotomy and histamine administration on them. Results show that bilateral gastric vagotomy in the control rats as well as in experimental diabetes lowers the acid secreting capacity of the parietal cells. In the diabetic rats, however, vagotomy does not further decrease the gastric acid secretion. Histamine stimulation augments the acid secretory response in the controls but this rise is substantially prevented in the diabetic state. Histamine challenge following vagotomy in normal controls elicits a sharp rise in gastric acid secretion though not to the same extent as seen in rats with intact vagi. In the diabetic rats however, histamine fails to augment acid secretion after vagotomy. Diabetes is thus seen to severely impair the acid secretory response of the parietal cells and their responsiveness to histamine.

Relación anatómica entre la superficie de la pared gástrica e inervación selectiva vagal / Relation between the gastric wall surface and vagal selective innervation

En el Departamento de Anatomía Normal de la Facultad de Medicina, de la Universidad de Chile, se realiza un trabajo de disección en 25 estómagos humanos adultos sin patología demostrada. La observación permite concluir que la porción vertical gástrica (superficie: 165,6 cm*) recibe 6 a 7 ramos nerviosos vagales. A su vez, la porción horizontal (superficie de 43,6 cm*) recibe 8 ramos vagales. El número de estos ramos nerviosos tiene relación inversa con respecto a la superficie de cada porción gástrica

Distribución parietal de los nervios vagos en curvatura menor del estomago / Parietal distribution of the vagus nerves in the low curvature of the stomache

Fueron estudiados 25 especímenes gástricos humanos disecando en detalle los ramos gástricos del nervio vago, en especial aquellos que llegan a la curvatura menor. Fue precisada la longitud promedio de esta curvatura gástrica. Se observó el número de ramos nervioso que llegan a la porción vertical y horizontal de la curvatura menor y se concluye que existe una relación inversa entre este número con la longitud de las porciones gástricas

Patrones de degeneración vagal en ratas albinas: estudio experimental / Patterns of vagal degenerations in albino rats: experimental study

Se presentan los hallazgos, en relación al patrón de degeneración nerviosa observando en estómagos de 25 ratas albinas, de las cuales un primer grupo fue sometido a vagotomía por las técnicas convencionales y un segundo grupo fue realizado con microcirugía. Los tiempos de supervivencia utilizados son: desde 24 horas hasta 5 meses. Los especímenes fueron procesados por parafina y luego sometidos a diversas técnicas de coloración y de impregnación, utilizándose el método de Nauta adaptado a la parafina y observados con microscopía de luz. Se correlacionan los patrones de degeneración, con el tipo de intervención quirúrgica practicada

Técnicas utilizadas en la preparación de bolsas gástricas para el estudio de la fisiología gástrica / Techniques used in the preparation of gastric pouch for the study of gastric function

El interés fundamental del presente trabajo es hacer una exposición de los modelos más prácticos y efectivos para la elaboración de bolsas gástricas con la finalidad de lograr los resultados más exactos posibles en el estudio de la fisiología gástrica. Se hace una descripción de la anatomía del estómago del perro, que es el animal más usado en las experiencias que actualmente se realizan para el mejor conocimiento de la influencia que los mecanismos neurohumorales ejercen sobre la secreción gástrica, por la gran similitud que ofrece su estómago tanto desde el punto de vista anatómico como fisiológico con el del hombre. Por características fácilmente evidenciables macroscópicamente, tanto en la serosa como en la mucosa y utilizando en ocasiones como complemento procedimientos colorimétricos, se puede delimitar la llamada área de la glándula oxíntica productora de ácido y pepsina y la denominada área de la glándula pilórica correspondiente al antro y secretora de la hormona gastrina. Se hace un señalamiento detallado tanto de la irrigación arterial y drenaje venoso como de la inervación autónoma, en especial de la inervación parasimpática cuyo conocimiento es indispensable para confeccionar bolsas gástricas que aseguren resultados confiables en el estudio de la fisiología gástrica. Se presentan varias técnicas ideadas por distintos autores para la elaboración de los modelos de bolsas, todas tendientes a hacerlas más sencillas, que las complicaciones derivadas de su propia elaboración sean menores y que las observaciones y experiencias que en ellas se realicen conduzcan a resultados lo más precisos posibles. Los modelos comprenden las variedades más usadas como son las bolsas fúndicas y antrales denervadas e inervadas, la bolsa gástrica total denervada e inervada y las bolsas transplantadas. En los estudios realizados por nosotros en la Sección Experimental del Hospital Vargas de Caracas y Escuela de Medicina Vargas de la UCV, hemos empleado en la mayoría de los casos para la elaboración de bolsas fúndicas denervadas la técnica de Heidenhain y para las bolsas fúndicas inervadas la técnica de Thomas con algunas modificaciones. Para la recolección del drenaje gástrico para estudio hemos utilizado la cánula de Thomas