Histological, histochemical and ultrastructural analysis of the gastric mucosa of the turbot (Scophthalmus maximus).

VIGLIANO, F.A.; QUINTÁNS, L.; BERMÚDEZ, R.; QUIROGA, M.I.; NIETO, J.M.

Foz do Iguaçu, Brasil/Puerto Iguazú, Argentina

Congreso; XV Pan American Congress of Anatomy; 2004

Pan American Association of Anatomy

The gastric mucosa of turbot (Scophthalmus maximus) was studied by light and electron microscopy in order to characterize their morphological and ultrastructural organization, as well as their histochemical composition. Small pieces of stomach were dissected out from six healthy turbot previously killed by severing the spine. The samples were fixed and processed by routine methods for light and transmission and scanning microscopy studies. On 1 μm thick paraffin sections, periodic acid-Schiff (PAS), PAS-Alcian blue (AB), and Aldehyde fuchsin-AB techniques were performed so as to assess the presence of carbohydrates in the gastric mucosa. The stomach of turbot was divided in three portions: cardial, fundic and pyloric regions. The lining epithelium was constituted by columnar epithelial cells with rodlet cells interposed between them. The epithelial cells showed short microvilli and abundant apical electron-dense granules, which were PAS-positive. These cells were joined by desmosomes and tight junctions. Gastric glands were only observed in the fundic region. They were tubuloacinar type, and their adenomere were constituted by pyramidal cells. These cells showed a well-developed rough endoplasmic reticulum, mitochondria, electron-dense granules and a membranous tubular network. Between the glands, endocrine cells were seen. The occurrence of short microvilli and neutral mucins in the columnar epithelial cells suggest that these cells could play a role in the absorption of nutrients. The gastric glands show a single cellular type unlike in mammals. These cells are ultrastructurally similar to parietal and principal cells, so they could participate in production of hydrochloric acid and pepsinogen.