Histologia e caracterização histoquímica do tubo gastrintestinal de Pimelodus maculatus (Pimelodidae, Siluriformes) no reservatório de Funil, Rio de Janeiro, Brasil

Abstract

ABSTRACT. Histology and histochemical characterization of the digestive tract of Pimelodus maculatus (Pimelodidae, Siluriformes) in Funil reservoir, Rio de Janeiro, Brazil. Histological structures of the digestive traits of Pimelodus maculatus La Cepède, 1803, in the Funil reservoir (22º30'-22º35'S; 44º35'-44º40'W) were described using haematoxilin-eosin (HE), trichome Gomori, periodic acid Schiff (PAS) and alcian blue (AB) pH 2.5 techniques. The main aim of this study was to detect the levels of glycoproteins (GPs) in the mucous tunic based in histochemical techniques and to characterize eventual alteration in the digestive tract of this species in a polluted system. Fifty-four adult individuals collected between April-2003 and July-2004 (TL=19-38 cm) were examined. The mucosa showed longitudinal folds in the buccopharyngeal cavity, with a stratified squamous epithelium. The oesophagus showed epithelium similar to buccopharyngeal cavity, with a predominance of mucous cells, which reacted strongly with the used methods. The stomach showed three regions: cardic, fundic and pyloric. The mucous tunic is continuously revested by a single cylindrical epithelium which showed positive reaction to AB and PAS only at the apical cells surface. The proper tunic has tubular glands that ramify gradatively, being a cellular type named oxyntopeptic, related to chloridric acid and pepsinogenic cells synthesis. The intestine showed vilosities, with the mucous tunic revested by a single cylindrical epithelium with striated planure and caliciform cells. The duodenum submucosa layer was located at the coledocum opening, as a single cylindrical epithelium lacking caliciforms cells, reacting positively with both PAS and AB. The eutrophic environment of Funil reservoir did not seem to influence morphologic patterns of the structures (oesophagus, stomach and intestine) and no modification was observed in the mucous cells activity. KEYWORDS.Morphology, glycoproteins, fishes, Pimelodidae. RESUMO. As estruturas teciduais do trato gastrintestinal dePimelodus maculatus La Cepède, 1803, do reservatório de Funil (22º30'-22º35'S; 44º35'-44º40'W) foram descritas através das técnicas de hematoxilina-eosina (HE), tricômico Gomori, ácido Periódico de Schiff (PAS) e alcian blue (AB) pH 2,5. Objetivou-se a detecção de glicoproteínas (GPs) na mucosa através de uma análise histoquímica e caracterização de possíveis alterações ao longo do trato digestório destes peixes neste sistema de elevado grau de alteração. Cinqüenta e quatro indivíduos adultos, coletados entre abril de 2003 e julho de 2004 (CT=19-38 cm) foram utilizados. Na cavidade bucofaríngea, a mucosa apresenta-se com pregas longitudinais e o epitélio é do tipo estratificado pavimentoso. O esôfago apresenta o mesmo tipo de epitélio da cavidade bucofaríngea, destacando-se a predominância de células mucosas que tiveram forte reação aos métodos utilizados. O estômago foi diferenciado em região cárdica, fúndica e pilórica. A mucosa é continuamente revestida por um epitélio simples cilíndrico que...

Immunohistochemical study of the digestive tract ofOligosarcus hepsetus

“…The same pattern was found in Prionotus carolinus by Blake [19] , but was not observed in Salmo trutta by Burnstock [20] or in P. maculatus by Santos et al [14] . The submucosa contains bundles of adipose tissue and blood vessels; the same was found in Dentex dentex (D. dentex) [21] .…”

“…In turn, acid GCs have high viscosity and are fundamental to trap particles [22] . The presence of these GCs was also reported in Anguilla anguilla [23] , D. dentex [21] , P. maculatus [14] , Cynoscion guatucupa (C. guatucupa) [24] , Pelteobagrus fulvidraco (P. fulvidraco) [25] and Hyphessobrycon anisitsi (H. anisitsi) [26] . The transition from the esophagus to the stomach is characterized by an abrupt change in the lining epithelium, which starts to present a single layer of columnar cells secreting mucus.…”

“…The gastric glands are composed of oxynticopeptic cells, which play a role similar to that of the principal and parietal cells in mammals, by synthesizing HCL and pepsinogen. In this case, we believe the glandular region has digestive functions while the non-glandular region only acts to carry the food to the gut with the epithelial secretions, with the help of the muscular layer, which in this region is thicker [14] . As seen in the esophagus, the stomach regions also contain well-developed longitudinal folds, whose function is to allow expansion of the organ's diameter to store a large volume of food [16,17] , another common characteristic of carnivorous fish species [30] .…”

“…We observed four layers: mucosa, submucosa, muscular and serosa. The muscularis mucosae is not present in the examined areas of the DT, unlike that observed in Pimelodus maculates (P. maculatus) [14] and Semaprochilodus insignis [15] . These authors assumed that the existence of muscular tissue between the lamina propria and submucosa aids in the elimination of the substances produced by the glands.…”

Effects of river damming in Neotropical piscivorous and omnivorous fish: feeding, body condition and abundances

“…Pimelodus present a very wide mouth opening, ability of store large amount of food in the stomach and histological adaptations to piscivory (Santos et al, 2007;Hahn & Fugi, 2008;Peretti & Andrian, 2008). These features allow eliciting the piscivorous behaviour by such species (Hahn & Fugi, 2008) providing better energy use and increase in the condition factor.…”