ABSTRACT
This study evaluated the properties of endogenous nitric oxide synthases (NOS) and annexin-A1 (ANXA1) and determined how they can be exploited in the N-methyl-N-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and myenteric denervation model. Male Wistar rats were treated with MNNG and/or aminoguanidine (AG) for 20 weeks. In another set of experiments, rats with nondenervated and denervated stomachs were treated with MNNG or water for 28 weeks. Fragments of the pyloric region were processed for histopathology, NOS activity, and immunohistochemistry to explore the activity and expression of constitutive (cNOS) and inducible (iNOS) NO synthase and their relationship with annexin-A1 (ANXA1) expression. NO inhibition by AG increased the percentage of animals with adenocarcinomas (~29%) compared with the untreated MNNG group (~4%). Myenteric denervation did not alter NOS activity. cNOS activity was significantly greater in nondernervated and denervated stomachs with or without lesions (P<0.001) than iNOS activity (P<0.01), as confirmed by immunohistochemistry. Further, cNOS activity in normal stomachs and outside the lesion area was considerably higher than inside it (P<0.01). By densitometric analysis of nondenervated and denervated stomachs, ANXA1 expression was modulated in epithelial and inflammatory cells (mast cells and neutrophils), wherein significant alterations were induced by lesion development and myenteric denervation. In conclusion, NO protects against the development of gastric adenocarcinomas. The pattern of ANXA1 expression was not associated with NOS activity or expression, suggesting that NO and ANXA1 act in gastric tumors in disparate pathways.
Subject(s)
Annexin A1/metabolism , Gastric Mucosa/metabolism , Nitric Oxide/metabolism , Stomach Neoplasms/metabolism , Stomach/innervation , Animals , Denervation , Immunohistochemistry , Male , Myenteric Plexus/physiology , Nitric Oxide Synthase/metabolism , Rats , Rats, Wistar , Stomach/pathology , Stomach Neoplasms/pathologyABSTRACT
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 3 x 1 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.
Subject(s)
Acetylcholinesterase/metabolism , Chagas Disease/drug therapy , Cholinergic Agents/pharmacology , Muscle, Smooth/innervation , Myenteric Plexus/pathology , Stomach/innervation , Acetylcholine/pharmacology , Adult , Carbachol/pharmacology , Case-Control Studies , Cell Count , Chagas Disease/enzymology , Cholinergic Agonists/pharmacology , Esophageal Achalasia/pathology , Esophageal Achalasia/surgery , Female , Humans , Male , Middle Aged , Muscle, Smooth/drug effects , Muscle, Smooth/enzymology , Neurons/cytology , Stomach/drug effects , Stomach/enzymologyABSTRACT
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.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Acetylcholinesterase/metabolism , Chagas Disease/drug therapy , Cholinergic Agents/pharmacology , Muscle, Smooth/innervation , Myenteric Plexus/pathology , Stomach/innervation , Acetylcholine/pharmacology , Case-Control Studies , Cell Count , Carbachol/pharmacology , Chagas Disease/enzymology , Cholinergic Agonists/pharmacology , Esophageal Achalasia/pathology , Esophageal Achalasia/surgery , Muscle, Smooth/drug effects , Muscle, Smooth/enzymology , Neurons/cytology , Stomach/drug effects , Stomach/enzymologyABSTRACT
In this work, two groups of Wistar rats were fed ad libitum, one with standard chow (22% protein) and the other with hypoproteic chow (8% protein), from the 210th to the 345th day of life. Compared to the animals fed with standard chow, the animals fed with hypoproteic chow exhibited hypophagia (ingestion about 30% lower), mean weight gain 4.46% lower, greater amount of retroperitoneal and peri-epididymal fat (19% on average), lower Lee index, decrease of total plasma proteins and plasma globulins and maintenance of plasma albumin. The quantitative and morphometric analysis of the NADH-diaphorase positive myenteric neurons yielded a larger number of small neurons and a smaller number of medium neurons in the animals subjected to the hypoproteic chow, demonstrating that the neuronal growth was affected by the diet. In the animals fed with hypoproteic chow, a 20% decrease in the NADH-diaphorase positive neurons of the forestomach and a 10% decrease in those of the glandular stomach were observed.
Subject(s)
Aging/physiology , Diet, Protein-Restricted , Malnutrition/physiopathology , Myenteric Plexus/physiopathology , Stomach/innervation , Stomach/physiopathology , Animals , Dihydrolipoamide Dehydrogenase/metabolism , Neurons/enzymology , Rats , Rats, WistarABSTRACT
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.
Subject(s)
Animals , Male , Rats , Anemia/etiology , Gastrectomy/methods , Iron/metabolism , Stomach/surgery , Vagotomy, Truncal , Anemia/metabolism , Feces/chemistry , Hematocrit , Hemoglobins/analysis , Intestinal Absorption , Iron/analysis , Rats, Wistar , Stomach/innervationABSTRACT
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%) (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.
Subject(s)
Anemia/etiology , Gastrectomy/methods , Iron/metabolism , Stomach/surgery , Vagotomy, Truncal , Anemia/metabolism , Animals , Feces/chemistry , Hematocrit , Hemoglobins/analysis , Intestinal Absorption , Iron/analysis , Male , Rats , Rats, Wistar , Stomach/innervationABSTRACT
The effect of cervical vagus nerve stimulation, gastric distension and CCK-8S administration was studied on the activity of 120 neurons located in the nucleus tractus solitarius (NTS) of anesthetized newborn lambs. One hundred cells responded to the three different inputs. The distribution of the cells in the NTS was from 3 mm rostral to 3 mm caudal to the obex, the major responsive cells being located at the level of the obex. Neurons were either excited or inhibited by gastric distension and CCK-8S, and the responses to these two stimuli were always in the same direction. A small number of cells responded to gastric distension and CCK-8S but not to vagus nerve stimulation. Injection of the CCK-A receptor antagonist 2-NAP abolished both the responses to CCK-8S and to gastric distension. The results are consistent with the idea that CCK-8S acts directly on vagal mechanoreceptive endings in the gastric corpus close to duodenum. These results from lambs may reflect the pathway by which gastric distension and peripheral CCK-8S modulate NTS cells activity during colostrum ingestion, which could in turn activate structures related to learning and memory processes involved in the development of mother preference.
Subject(s)
Sincalide/pharmacology , Solitary Nucleus/drug effects , Solitary Nucleus/physiology , Stomach/innervation , Stomach/physiology , Anesthesia , Animals , Animals, Newborn , Aspartic Acid/analogs & derivatives , Aspartic Acid/pharmacology , Catheterization , Electrophysiology , Microelectrodes , Naphthalenesulfonates/pharmacology , Receptor, Cholecystokinin A/agonists , Receptor, Cholecystokinin A/antagonists & inhibitors , Receptor, Cholecystokinin A/physiology , Sheep , Vagus Nerve/physiologyABSTRACT
The NADPH-diaphorase (NADPH-d) positive myoenteric neurons from the body of the stomach of rats with streptozotocin-induced diabetes with or without supplementation with acetyl-L-carnitine (ALC) were evaluated. At the age of 105 days the animals were divided into four groups: normoglycaemic (C), normoglycaemic supplemented with ALC (CC), diabetic (D) and diabetic supplemented with ALC (DC). The supplementation with ALC (200 mg/kg body weight/day) to groups CC and DC was made during 105 days. After this period the animals were killed and the stomach removed and subjected to the histochemical technique of NADPH-d for the staining of the neurons of the myoenteric plexus. The area of 500 neurons of each group was investigated, as well as the neuronal density in an area of 23.84 mm(2) in each stomach. ALC promoted reduction (P < 0.05) of fasting glycaemia, water ingestion and areas of the profiles of the cell bodies of the NADPH-d neurons in the diabetic animals. The density of these neurons was not statistically different in the groups studied. It is suggested, therefore, a moderate neuroprotective effect of ALC, because the diminishment of the areas of the neuronal profiles in the supplemented diabetic animals, although being statistically significant relative to the non-supplemented diabetics, was not sufficient to equal the values from the non-diabetic controls.
Subject(s)
Acetylcarnitine/pharmacology , Diabetes Mellitus, Experimental/metabolism , Neurons/drug effects , Nootropic Agents/pharmacology , Stomach/innervation , Animals , Blood Glucose/metabolism , Dietary Supplements , Male , NADPH Dehydrogenase/metabolism , Neurons/metabolism , Random Allocation , Rats , Rats, Wistar , Submucous Plexus/drug effectsABSTRACT
Abnormal gastric motility function could be related to gastric electrical uncoupling, the lack of electrical, and respectively mechanical, synchronization in different regions of the stomach. Therefore, non-invasive detection of the onset of gastric electrical uncoupling can be important for diagnosing associated gastric motility disorders. The aim of this study is to provide a wavelet-based analysis of electrogastrograms (EGG, the cutaneous recordings of gastric electric activity), to detect gastric electric uncoupling. Eight-channel EGG recordings were acquired from 16 dogs in basal state and after each of two circular gastric myotomies. These myotomies simulated mild and severe gastric electrical uncoupling, while keeping the separated gastric sections electrophysiologically active by preserving their blood supply. After visual inspection, manually selected 10 min EGG segments were submitted to wavelet analysis. Quantitative methodology to choose an optimal wavelet was derived. This 'matching' wavelet was determined using the Pollen parametrization for 6-tap wavelet filters and error minimization criteria. After a wavelet-based compression, the distortion of the approximated EGG signals was computed. Statistical analysis on the distortion values allowed us to significantly (p < 0.05) distinguish basal state from mild and severe gastric electrical uncoupling groups in particular EGG channels.
Subject(s)
Algorithms , Diagnosis, Computer-Assisted/methods , Electromyography/methods , Gastroparesis/diagnosis , Muscle, Smooth/physiopathology , Stomach/innervation , Stomach/physiopathology , Animals , Computer Simulation , Dogs , Electrodiagnosis/methods , Female , Gastroparesis/physiopathology , Male , Models, Biological , Reproducibility of Results , Sensitivity and Specificity , Signal Processing, Computer-AssistedABSTRACT
The influence of myenteric denervation on the development of gastric tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied after chemical denervation of the rat stomach with benzalkonium chloride (BAC). Three groups were evaluated: control, denervated and denervated with pyloroplasty. Random bred male Wistar rats were given MNNG in drinking water (100 mg/l) for 28 weeks. After the sacrifice of animals, the stomachs were removed for morphological study. BAC reduced myenteric neurons number, increased the gastric mucosa area and decreased the adenocarcinomas number and size. This decrease was more evident when denervation was associated with pyloroplasty. These results indicate that myenteric denervation reduces the incidence of experimentally induced gastric tumors.
Subject(s)
Stomach Neoplasms/pathology , Stomach Neoplasms/prevention & control , Sympathectomy, Chemical , Animals , Benzalkonium Compounds/pharmacology , Carcinogens , Male , Methylnitronitrosoguanidine , Neoplasms, Experimental/prevention & control , Rats , Rats, Wistar , Stomach/innervationABSTRACT
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
Subject(s)
Animals , Male , Female , Stomach/innervation , Intestine, Small/innervation , Vagus Nerve/anatomy & histology , Fluorescent Dyes , Microscopy, Fluorescence , Rats , Rats, Sprague-Dawley , Afferent PathwaysABSTRACT
UNLABELLED: Delayed gastric emptying of solid food is greater after proximal gastric vagotomy (PGV) than after anterior lesser curve seromyotomy with posterior truncal vagotomy (ASPTV) and may be due to the hypoxia in the gastric wall and mainly in the gastric pacemaker. PURPOSE: To verify if operative devascularization of the lesser curve and the gastric fundus could affect the entire stomach and particularly the pacemaker area. METHODS: Measures of intraoperative oxyhemoglobin saturation (SpO2) were taken by pulse oximetry on the anterior gastric wall in 20 patients with chronic duodenal ulcer, randomly allocated in two groups of 10 individuals for surgical treatment, by PGV or ASPTV. RESULTS: Measurements, before partial fundoplication, showed that the area of the proximal lesser curve and the gastric fundus had a significant decrease in the SpO2 when compared to the gastric corpus (p < 0,05); the SpO2 was not reduced significantly by the procedures on the pacemaker area; the ligature of short gastric vessels, in association with PGV or ASPTV, reduced significantly the SpO2 (p < 0,05); and, PGV resulted in a SpO2 significantly lower than in ASPTV (p < 0,05). CONCLUSION: When PGV is associated with the ligature of the short gastric vessels, it causes acute ischemic changes in the proximal lesser gastric curve and in the fundus more intensively than ASPTV. The gastric pacemaker area does not present hypoxia immediately after operative procedures.
Subject(s)
Duodenal Ulcer/surgery , Oximetry , Stomach/surgery , Vagotomy, Proximal Gastric , Vagotomy, Truncal , Analysis of Variance , Biological Clocks , Gastric Fundus/innervation , Humans , Stomach/innervationABSTRACT
AIM: In the present study we evaluated the effects of gastric myenteric denervation using benzalkonium chloride (BAC) on the time for gastric emptying, as well as gastric secretion, and mucosal epithelial cell size and population in rats. METHODS AND RESULTS: Wistar rats were treated with topical serosal application of BAC to the stomach. Control animals received saline. Ninety days after surgery, gastric emptying time, gastric acid secretion and serum gastrin levels were studied. Next, the animals were sacrificed and the stomachs were removed, fixed in formalin and histologically processed for histomorphometry of the height, area and volume of the glandular portion, and volume and population of mucous, chief, parietal, G- and labelled cells. BAC animals showed a significant delay in gastric emptying and an increase in gastric acid secretion and serum gastrin levels. These animals also presented a significant reduction of myenteric neuron number, hypertrophy of parietal and chief cells, hyperplasia of G cells and an increase in the gastric mucosa area. CONCLUSION: The absence of the myenteric plexus seems to protect the stomach from the hyperplastic effects of hypergastrinemia. Gastric food stasis may act as a factor triggering morphological and functional alterations of the gastric epithelium. Although gastric food stasis is a common finding in medical practice, its physiopathological consequences are poorly understood and have not been frequently discussed in the literature.
Subject(s)
Gastric Emptying , Gastric Mucosa/physiology , Gastrins/blood , Stomach/physiology , Animals , Benzalkonium Compounds , Chief Cells, Gastric/pathology , Detergents , Gastric Acid/metabolism , Gastric Acidity Determination , Gastric Mucosa/metabolism , Gastric Mucosa/pathology , Gastrin-Secreting Cells/pathology , Hyperplasia , Muscle Denervation/methods , Muscle, Smooth/innervation , Muscle, Smooth/physiology , Myenteric Plexus/drug effects , Organ Size , Parietal Cells, Gastric/pathology , Rats , Rats, Wistar , Stomach/innervationABSTRACT
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.
Subject(s)
Intestine, Small/innervation , Stomach/innervation , Vagus Nerve/anatomy & histology , Afferent Pathways , Animals , Female , Fluorescent Dyes , Male , Microscopy, Fluorescence , Rats , Rats, Sprague-DawleyABSTRACT
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
Subject(s)
Animals , Mice , Dihydrolipoamide Dehydrogenase , Stomach/enzymology , Case-Control Studies , Stomach/innervation , Nutrition Disorders , Rats, Wistar , Enteric Nervous System/enzymologyABSTRACT
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
Subject(s)
Animals , Male , Female , Rats , Celiac Plexus/anatomy & histology , Vagus Nerve , Duodenum , Stomach/innervation , Liver/innervation , Pancreas , PylorusABSTRACT
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
Subject(s)
Animals , Male , Rats , Diabetes Mellitus, Experimental/pathology , Myenteric Plexus/pathology , Stomach/innervation , Diabetes Mellitus, Experimental/metabolism , Dihydrolipoamide Dehydrogenase , Rats, Wistar , StreptozocinABSTRACT
Convergence of gastric and hepatic information in the nucleus of the solitary tract (NTS) was investigated by single-pulse electrical stimulation of the hepatic and the gastric branches of the vagus. Facilitation induced by both stimuli occurred most often in responses of neurons in the NTS, indicating convergence of information there. In a second experiment using gastric distension and portal infusion of glucose to analyze such convergence, activation by gastric distension and suppression by portal glucose was the most prominent combination of responses to both stimuli. This confirmed the results of electrical stimulation, because distension increases the firing rate of gastric afferents and glucose infusion decreases the firing rate of hepatic afferents. Analysis of the responses to varying degrees of gastric distension revealed that some NTS neurons are activated by weak distension, but inhibited by strong distensions.
Subject(s)
Brain Stem/physiology , Liver/innervation , Neurons/physiology , Stomach/innervation , Animals , Brain Stem/cytology , Chemoreceptor Cells/physiology , Electric Stimulation , Glucose/administration & dosage , Infusions, Intravenous , Male , Mechanoreceptors/physiology , Rats , Rats, Sprague-Dawley , Receptors, Cell Surface/physiologyABSTRACT
The general morphology of the intramural innervation of the myenteric plexus of the axolotl stomach has been investigated using antisera raised against neuron-specific enolase and a microtubule-associated protein. Additionally, the occurrence of serotonin and several peptidergic neurotransmitter/neuromodulator substances was studied. Immunoreactivity for galanin, vasoactive intestinal polypeptide, substance P and neuromedin U was found in both fibres and intrinsic perikarya, whereas the serotonin and calcitonin gene-related peptide-like-substance-containing nerve fibres seemed to be of extrinsic origin. The axolotl stomach myenteric plexus appeared to be devoid of enkephalin-, neuropeptide Y-, somatostatin- and bombesin-like immunoreactive nerve fibres and nerve cell bodies. Double labelling experiments revealed the presence of a subpopulation of substance P/calcitonin gene-related peptide-like immunoreactive nerve fibres. Contrary to mammals, no coexistence of neuromedin U and substance P was found. Our findings illustrate that besides a number of similarities, considerable species differences exist between urodeles and anurans with regard to the organization of the enteric nervous system.