Estudio histológico e histoquímico de intestino de juveniles de pejerrey (Odontesthes bonariensis).

AGELET, L.; MÁNES, J.; VIGLIANO, F.A.; CERUTTI, P.

Rosario, Argentina

Congreso; V Congreso y XXII Reunión Anual de la Sociedad de Biología de Rosario; 2002

Sociedad de Biología de Rosario

In this study the tissue arrangement and the different cells that make up the intestine of Odontesthes bonariensis are determined. Samples from fifty specimens were taken, fixed in 10% formaldehyde and embedded in paraffin. Sections of 2 μm thickness were stained with histological and histochemical techniques. Results showed that the digestive tract had three tunicae: mucosa, muscular and serosa. The muscular lamina of mucosa was not observed. Histologically, intestinal mucosa showed large primary villi from which secondary ones branched off. Microscopically, these villi were made up of a pseudostratified epithelium with mucous cells and a central axis of lax connective tissue that derived from the lamina propria. In the centre of this structure a blood vessel was observed. The lamina propria did not show glands. The muscular layer had smooth muscular fibres in two strata: circular internal and longitudinal external. The serosa was typical. Based on the mucosa structure an anterior, transitional and posterior region were observed. In the former one primary and secondary villi were high and numerous occupying the lumen almost completely. The epithelial cells found on the lumen were column-like, had a brushy edge and were P.A.S. positive. Mucous cells showed a heterochromatin basal nucleus with large vacuole positive to Alcian blue in their apical portion. Rodlet cells with cytoplasmatic acidophilic granules, were found intercalated between epithelial cells. In the transitional region, the mucosa presented thinner primary villi and shorter secondary villi. In the posterior region no secondary villi were seen. The number of calceiform cells decreased considerably in this region.