ENDOCRINE AND GOBLET CELLS DISTRIBUTION IN THE INTESTINE OF BRAZILIAN FISH TAMBAQUI AND HYBRID SPOTTED SORUBIM

Raquel T. Pereira, Thaiza R. Freitas, Mariel N. Tavares, Murilo C. B. Piva, Maarten J. van Schoonhoven, Priscila V. Rosa
 
Department of Animal Science
Federal University of Lavras UFLA
Lavras, MG, Brazil raqueltpr@gmail.com
 

Endocrine cells are a highly specialized mucosal cell subpopulation involved in the producing of peptide hormones. CCK-8 stimulates pancreatic and bile secretions and NPY is the most potent orexigenic factor known. The main secretory product of goblet cells, mucin, forms a mucus layer coating the gut epithelium acting as the front line of innate host defense. The distribution of endocrine cells producing peptide hormones and goblet cells along the intestine of tambaqui Colossoma macropomum and hybrid spotted sorubim Pseudoplatystoma reticulatum  Leiarius marmoratus were assessed in this study. Intestine samples from 5 from tambaqui and 4 from hybrid spotted sorubim were collected in different segments of the midgut and hindgut.

Endocrine cells CCK-8+ and NPY+ were identified using immunohistochemistry. The goblet cells producing acid and neutral mucins were stained by Alcian Blue (AB) and Periodic Acid Schiff (PAS), respectively. Average number of ECs per mm-2 epithelial mucosa was obtained from ANOVA and Tukey's test. S.E.M: standard error mean and p-value set at p<0.05 (Fig. 1). For tambaqui, the endocrine cells CCK+ were more uniformly distributed along the intestine, except for the lower density at CP (pyloric caeca). Endocrine cells NPY+ density was higher in T1 and T2 (71%). Goblet cells AB+ highest density was recorded in T2 (37%) while PAS+ had wider distribution from T1 to T3 (27%, 31%, and 26%, respectively). For hybrid spotted sorubim, the density of endocrine cells CCK+ and NPY+ were higher in the midgut on P1 (60%) and P1 and P2 (73%, likewise tambaqui), respectively. Goblet cells AB+ and PAS+ were more concentrated in the hindgut, PP accounting for 45% and 53%, respectively. Endocrine and goblet cells density were different and related to the anatomical features of the digestive tract in each fish. Although particularities exist among species, it seems that there is a distribution pattern of cells type that can be justified by the feeding habits.