Distribution of enteroglucagon- and peptide YY-immunoreactive cells in the intestinal mucosa of germ-free and conventional mice

Arantes, Rosa Maria Esteves; Nogueira, Ana Margarida Miguel Ferreira

doi:10.1007/s004410050908

Cited by 46 publications

(31 citation statements)

References 28 publications

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“…Samples (small intestine) were fixed in 4 % formaldehyde and processed by inclusion in paraffin for microtomy. For analysis of intestinal lesions, the tissues were rolled up (filled rolls) and fixed in Bouin solution as described by Arantes & Nogueira (1997). Sections 4-5 mm thick were stained with haematoxylin/eosin (HE), coded and analysed through optical microscopy by a single pathologist who was unaware of the experimental conditions for each group.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of mucositis induced by irinotecan after microbial colonization in germ-free mice

et al. 2015

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Mucositis is one of the most debilitating side effects of chemotherapy and some previous studies suggest a role for indigenous microbiota in the course of this pathology. Therefore, the aim of our study was to evaluate the differences in phenotype between germ-free (GF) and conventional (CV) mice, and the role of b-glucuronidase-producing bacteria in the development of irinotecan treatment in a murine model. After mucositis induction, CV mice showed a significant increase in all inflammatory parameters when compared to GF mice. CV animals also showed more lesions of the intestinal epithelium, coherent with their higher intestinal permeability. The conventionalization of GF animals reversed their phenotype to that found in CV mice. In addition, gnotobiotic mice monoassociated with an Escherichia coli strain producing b-glucuronidase showed an increased permeability when compared to gnotobiotic mice monoassociated with an E. coli strain deleted for the gene encoding b-glucuronidase, but these did not show any differences in the influx of neutrophils, eosinophils or histological characteristics. Our data confirmed that components of the gut microbiota are involved in the signs of mucositis. Nevertheless, other mechanisms than this enzyme are involved in the irinotecan treatment, since the monoassociation was not able to restore the entire phenotype observed in the CV animals with irinotecan treatment in our murine model.

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Section: Methodsmentioning

confidence: 99%

Evaluation of mucositis induced by irinotecan after microbial colonization in germ-free mice

et al. 2015

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“…The neuronal loss observed in the current study could only be detected due to the extensive sampling technique described by Arantes and Nogueira [40], since the colonic acometiment is segmental.…”

Section: Discussionmentioning

confidence: 49%

“…The prefixed segments were then rolled into a spiral with the mucosa facing inward, so as to form a "Swiss roll" similar to that described by por Calvert, Otsuka e Satchithanandam with adaptations by Arantes and Nogueira. The material was routinely processed for paraffin embedding and consecutive 4 µm thick histological sections were obtained [39,40].…”

Section: Tissue Sampling and Preparationmentioning

confidence: 99%

Nitrergic Myenteric Neurons are Spared in Experimental Chagasic Megacolon

Ricci¹,

Campos²,

Cartelle³

et al. 2016

J Neuroinfect Dis

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Chagas disease is a chronic disorder caused by the Trypanosoma cruzi protozoan. The infection causes alterations to the enteric nervous system such as megaesophagus and megacolon. There is evidence of denervation of myenteric ganglia. The intense parasitism of acute phase affects neuronal integrity but contrasts with the absence of parasites and the discreet inflammatory process of chronic phase, indicating a progressive injury mechanism that needs to be better understood in the megacolons. The potential selectivity of enteric neurons classes affected by the progression of the disease is not yet clear. Nitrergic neurons which co-localize other neurotransmitters represent the most common inhibitory neuron of the ENS. Recently a chronic stage of the Chagas disease was reproduced experimentally in a suitable murine model of megacolon. Considering the limitation of studying human intestine and the controversy on the pattern of nNOS involvement in chagasic megacolon, we decided to assess the nitrergic neurons in the myenteric plexus of mice. We used antibodies against structural protein gene product 9.5 (PGP 9.5) and functional neuronal nitric oxide synthase (n-NOS) at the acute and chronic phase of the disease to quantify myenteric ganglionar neurons in the colon of infected and non-infected mice. We found a reduction in the ganglionar number of neurons detected by anti-protein gene product 9.5 antibodies in colon from mice at the chronic stage. However, the number of nitrergic neurons per ganglia remained unchanged along the acute to phase chronic of the disease. Our findings indicate a long-term preservation of nitregic neurons detrimental to other classes of enteric in our model of experimental Chagas disease. We propose that differential loss of enteric neurons is at least one of the structural substrate for the development of the longterm morphfunctional changes that lead to the megacolon.

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“…Each segment was opened along the ante-mesenteric border, the contents were removed and the length was measured. The intestinal segments were processed as described previously (Arantes & Nogueira, 1997). Briefly, after pre-fixation in formaldehyde/PBS (1 : 10, pH 7.2) for 90-120 min, the segments were rolled up to form the so-called 'Swiss roll' and fixed for a further 18-20 h. The tissue fragments were dehydrated in alcohol solution using an automated tissue processor (Ti-tertek Autotechnicon Company) and then embedded in paraffin.…”

Section: Methodsmentioning

confidence: 99%

Effects of oxidative stress on the virulence profile of Prevotella intermedia during experimental infection in gnotobiotic mice

Santos

Diniz

Silva

et al. 2007

Journal of Medical Microbiology

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Prevotella intermedia is a component of the indigenous microbiota but is also responsible for anaerobic infections of the gastrointestinal tract and oral cavity. The aim of the present study was to investigate the influence of oxidative stress on the in vivo pathogenicity of P. intermedia. Germ-free mice were challenged intraperitoneally with parental (wt) or oxidative stress adapted (aero) strains. Bacterial virulence was evaluated by histopathology, hyperaemia and blood analysis [C-reactive protein (CRP), serum albumin and white blood cells (WBCs)], 3 and 10 days after challenge. CRP levels and WBC count were higher in animals challenged with the aero strain, and the albumin level was lower in this group, only 10 days after infection (P<0.05). Body weight gain was significantly reduced whereas hyperaemia and ratios of spleen/organ weight were increased in animals challenged with the aero strain (P<0.05). The liver of animals challenged with the aero strain showed hyperaemia, vasodilatation as well as an increase in the number of inflammatory cells and liver/organ weight ratio (P<0.05). Similar, but more discrete, alterations were observed in the small intestine of animals challenged with the aero strain. Studies on stress responses of this putative pathogen may help to better understand the aggressive potential and virulence markers of anaerobic bacteria.

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Distribution of enteroglucagon- and peptide YY-immunoreactive cells in the intestinal mucosa of germ-free and conventional mice

Cited by 46 publications

References 28 publications

Evaluation of mucositis induced by irinotecan after microbial colonization in germ-free mice

Evaluation of mucositis induced by irinotecan after microbial colonization in germ-free mice

Nitrergic Myenteric Neurons are Spared in Experimental Chagasic Megacolon

Effects of oxidative stress on the virulence profile of Prevotella intermedia during experimental infection in gnotobiotic mice

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