Estudo morfoquantitativo dos neurônios mioentéricos NADH-diaforase positivos do íleo de ratos (<em>Rattus norvegicus</em>) da linhagem Holtzman

Abstract

The myenteric plexus has a regular characteristic morphological pattern for each segment of the digestive tube and for each species of animal. Considering the lack of data pertaining to the mentioned plexus in rats of Holtzman lineage, the objective of this investigation was to carry out a morpho-quantitative study of the myenteric neurons in the ileum, by means of histological sections and whole-mount muscular preparations treated by the NADH-diaphorase method. The profiles of the cell bodies (CB) of the neurons in the mesenteric and antimesenteric regions were counted and measured. The neurons were classified according to the dimensions of the CBs. NADH-dp myenteric neurons were observed grouped together into ganglia in the muscular tunica. The mean neuronal density was 985.8 ± 195.4 neurons/8.96 mm2 in the antimesenteric region and 1267.8 ± 259.92 neurons/8.96 mm2 in the mesenteric region. The incidences of small, medium and large neurons were 14.4, 82 and 3.6% in the antimesenteric region and 14.6, 70.8 and 14.4% in the mesenteric region, respectively. It was concluded that ganglionated arrangements and medium-sized NADH-dp neurons predominated in the myenteric plexus of adult Holtzman rats. The results observed indicated that the NADH-dp myenteric neurons of the ileum of Holtzman rats are similar to those of rats of Wistar lineage with respect to their localization, ganglionated arrangement and the predominance of neurons with medium-sized CBs.