Alterações morfométricas no plexo mioentérico do cólon menor equino distendido experimentalmente

Abstract

RESUMO.-O cólon menor dos equinos é frequentemente acometido por afecções obstrutivas, sendo a disfunção da motilidade uma complicação comum após o tratamento cirúrgico. Este transtorno pode estar relacionado com lesões no plexo mioentérico ocorridas durante a distensão intestinal, contudo pouco se sabe sobre sua fisiopatologia. O objetivo deste estudo foi avaliar as alterações morfológi-cas na inervação mioentérica em segmentos de cólon menor de eqüinos submetidos à distensão intraluminal com pressão suficiente para promover redução da perfusão microvascular (isquemia parcial) da parede intestinal. Nove eqüinos foram submetidos à distensão do cólon menor por 4h. Fragmentos da parede intestinal foram colhidos antes e ao final da distensão, após 1,5 e 12 horas de reperfusão no segmento experimental e ao final do procedimento em The equine small colon is frequently affected by obstruction, and intestinal motility dysfunction is a common complication after its surgical treatment. This fact may be related to myoenteric plexus lesion caused by distention; however, little is known about the pathophysiology of this condition. The objective of this study was to evaluate the morphological alterations in the myoenteric inervation of segments of small colon of horses subjected to intraluminal distension with reduction of the microvascular perfusion (partial ischemia) of the intestinal wall. Nine horses were used to promote distension of on segment of small colon for 4 hours. Samples of intestinal wall were collected before and at the end of the distension, after 1.5 and 12 hours of reperfusion in the experimental segment and at the end of the procedure in a different distant segment. Samples were processed and histological sections were stained with cresyl violet for the morphometric studies. An image analyzer software was used to measure perimeter, diameter, and area of the neuronal body, nucleus and nucleolus of the neurons and the areas of the cytoplasm and nucleoplasm. Significant reductions (P<0.05) in the areas of the neuronal body and cytoplasm were detected at the end of intestinal distension, returning to the basal values during the reperfusion. In conclusion, intraluminal distension promoted changes in the morphology of the neurons of myoenteric plexus. These morphological modifications may be associated to the motility dysfunction frequently observed in clinical cases.INDEX TERMS: Small colon, distension, myoenteric plexus, horse.

Comparison between the techniques of inclusion in glycol methacrylate (GMA)- based plastic resin and paraffin for evaluation intestinal morphometry in horses

“…In previous reports, histomorphometric evaluation of the intestinal mucosa of horses through routine paraffin embedding has been recorded ( Batista et al, 2005 ; Faleiros et al, 2007 ; Lucas et al, 2005 ; Mendes et al, 2009 ; Milne et al, 2010 ). However, GMA has several advantages over conventional paraffin-based methods ( Amaral et al, 2004 ).…”

“…Intestinal biopsy processing techniques have remained the same in recent years and include fixation in 10% formalin and embedding in paraffin ( Lima et al, 2020 ; Rocchigiani et al, 2021 ). This technique has been widely used in research and intestinal morphometry in horses ( Melo et al, 2014 ; Mendes et al, 2009 ). However, the inclusion of biological tissues in plastic resin is advantageous when compared to embedding them in paraffin, which is one of the techniques of choice for processing tissue samples for research ( Chiarini-Garcia et al, 2011 ).…”

Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

“…In the Auerbach plexus, the neuron numbers and morphology, PGP9.5-IR area and GFAP + area were evaluated. In ganglion neurons, the measurements of the cell body and the nuclear and cytoplasmic area and perimeter, in addition to the ratios between the nuclear and cell body area, were assessed ( Barbosa et al 2009 , Mendes et al 2009a ). In addition, the number of intact neurons was quantified and evaluated in relation to the ganglionic area ( Tafuri 1957 ).…”

<b>Avaliação de nova técnica de biopsia intestinal assistida por videolaparoscopia em equinos</b>

“…A serosa é a camada mais externa da alça intestinal e está em contato com os demais órgãos da cavidade abdominal. É composta por tecido conectivo frouxo, colágeno e tecidos elásticos, que permitem com que o segmento de intestino se distenda ou se compacte, adaptando-se ao conteúdo presente (líquido, sólido ou gasoso) (SAMUELSON, 2007;FENOGLIO-PREISER et al, 2008 (FEARY et al, 2006;TAYLOR et al, 2006;KALCK, 2009;MENDES et al, 2009;PUSTERLA et al, 2013;PIRIE et al, 2014 (LINDBERG et al, 1996;SCHUMACHER et al, 2000;PACKER et al, 2005).…”

“…A DII pode ser classificada de acordo com a predominância de grupos celulares presentes nos segmentos afetados, sendo que quatro tipos diferentes de enterites e colites podem ser identificados: enterocolite granulomatosa, linfoplasmocitica, eosinofílica e doença multissistêmica eosinofílica epiteliotrópica (SCHUMACHER et al, 2000;MAIR et al, 2006;KALCK, 2009 (ALLEN et al, 2009;GUIMARÃES-LADEIRA et al, 2009;PUSTERLA et al, 2013;GUTTMANN et al, 2014 (SCHOLES et al, 1993;UZAL et al, 1993;ARAYA et al, 2002;WALES et al, 2006;MILNE et al, 2010;MAIR et al, 2013;PIRIE et al, 2014 (LEAL et al, 2001;TAYLOR et al, 2006 (HOOGMOED et al, 2000;THOMASSIAN, 2005;BLINKSLAGER et al, 2009;GROSCHE et al, 2011;LEVI et al, 2012 (MESCHTER et al, 1990;LUCAS et al, 2005;PACKER et al, 2005;MCCONNICO et al, 2008;HOLCOMBE et al, 2009;MENDES et al, 2009;HOPSTER-IVERSEN et al, 2011 (TAYLOR, 2002;BAIN et al, 2004;SCHAMBOURG et al, 2006;BRACAMONTE et al, 2008).…”