Imuno-histoquímica das células neuroendócrinas do tubo gastrintestinal de Pimelodus maculatus (Siluriformes, Pimelodidae) dos reservatórios de Funil e Santa Branca. / Immunohistochemistry of neuroendocrine cells of the gastrointestinal tube of Pimelodus maculatus (Siluriformes, Pimelodidae) from Funil and Santa Branca reservoirs.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The objective of this work is to analyze the influence of habitat on the regional distribution and relative frequency of gastrointestinal neuroendocrine cells that secrete cholecystokinin octapeptide (CCK-8), gastrin and serotonin (5-HT) in Pimelodus maculatus. All told, 18 fish were utilized, 12 of them taken from Funil Reservoir in the state of Rio de Janeiro and 6 from Santa Branca Reservoir in the state of São Paulo. The fish were sacrificed by hypothermia and dissected in the field. Fragments of the stomach (fundic and pyloric region) and intestine were fixed in Bouins fluid, processed and embedded in paraffin. Sections 5 μm thick were placed on slides previously treated with poly-L-lysine and then submitted to immunohistochemical analysis. Three types of immunoreactive (IR) cells were identified in the gastric and intestinal mucosa of P. maculatus. The antibodies used were anti-CCK-8, anti-gastrin and anti-5-HT. Cells IR to CCK-8, gastrin and 5-HT were found in the stomach and intestine of the fish from both reservoirs. According to the Mann-Whitney nonparametric test, there was a significant difference in the relative frequency of cells between the two reservoirs and regions of the gastrointestinal tube. The cells IR to CCK-8 were more abundant in the pyloric region than in the fundic region of the stomach. In the intestine they were of the open type. The cells IR to gastrin, the predominant cell type, were abundant and strongly marked in the three regions studied. The cells IR to 5-HT were more abundant in the fish from Funil Reservoir, and their frequency was greatest in the pyloric region of the stomach.

ASSUNTO(S)

ecologia imuno-histoquímica. trato gastrintestinal neuroendocrine cells células neuroendócrinas immunohistochemistry. pimelodus maculatus gastrointestinal tract

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