Navegando por Palavras-chave "myenteric plexus"

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    Endocrine cells in the denervated intestine
    (Blackwell Science Ltd, 2000-08-01) Santos, G. C.; Zucoloto, S.; Garcia, S. B.; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    This study deals with the effects of myenteric denervation of the proximal jejunum on endocrine cell population of the crypt-villus unit, 5 months after treatment with benzalkonium chloride (BAC). Male Wistar albino rats weighing on average 100 g were allocated to two groups: the BAC group - the proximal jejunal serosa was treated with 2 mM BAC for 30 min, and the control group - treated with saline solution (0,9% NaCl). There was a significant reduction in neurone number in the jejunal myenteric plexus of the BAC group and the endocrine cell population (serotoninergic and argyrophilic cells) was significantly increased in this intestine segment. in conclusion, the present findings provide further evidence that the myenteric denervation induced by BAC may lead to the development of a local imbalance of the neurotransmitters, with a consequent induction of enteroendocrine cell (argyrophilic and serotoninergic cells) hyperplasia in the crypt and villus.
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    Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus
    (Assoc Bras Divulg Cientifica, 1997-05-01) Maifrino, Laura Beatriz Mesiano [UNIFESP]; Prates, José Carlos [UNIFESP]; DeSouza, R. R.; Liberti, E. A.; Universidade de São Paulo (USP); INST DANTE PAZZANESE CARDIOL; Universidade Federal de São Paulo (UNIFESP)
    The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE) histochemical technique in whole-mount preparations, Neuronal density was 1,500 +/- 116 neurons/cm(2) (mean +/- SEM) in the esophagus, 8,900 +/- 1,518 in the stomach, 9,000 +/- 711 in the jejunum and 13,100 +/- 2,089 in the colon, The difference in neuronal density between the esophagus and other regions was statistically significant, The neuron profile area ranged from 45 to 1,100 mu m(2). The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles, Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease.