Are there histological changes in the intestine of birds in a stress situation?

PADRONES MN; FILIPPA VP; CID, FD; CHEDIACK, JG

San Luis

Congreso; Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2019

Sociedad de Biología de Cuyo

Anyalteration of homeostatic stability is a stressful situation for living beings.This alteration triggers physiological changes in response to a stresssituation. In birds this response is related to the release of glucocorticoids.Glucocorticoids influence the function of several tissues. Although there are alarge number of studies that have investigated histological alterations ofglucocorticoids in mammals, the knowledge of this area in birds is limited. Themain glucocorticoid in birds is corticosterone (CORT). In previous experimentsour research group found a marked relationship between treatment with CORT andan increase in the heterophil to lymphocyte index (H/L), an indicator of stressin birds. We found a decrease in body mass when the birds were treated withCORT; however, the intestine mass was not affected by CORT treatments. Theobjective of this work was to determine histological alteration in theintestine of Passer domesticus inresponse to different doses of exogenous CORT. To achieve our goal, 16 sparrowswere acclimated to a laboratory condition with water and food al libitum, themseparating randomly in four groups and each group were exposed to a differentconcentration of CORT in drinking water ad libitum (control, 20, 40 and 80mg/l) for 72 hours emulating a long-term stress situation. After the expositionthe intestine was removed and a portion of proximal section was fixed in Bouinsolution. Then the intestinal pieces were dehydrated and embedded in paraffin.Histological studies were performed on 5µm sections, stained byhematoxylin-eosin coloration, and examined by a light microscope. Amorphometric analysis was performed using the software Image Pro Plus 5.0. Themeasured parameters were: intestinal perimeter, muscle layer, mucosa thickness,crypt width, villus width and villus height. The data were statisticallyanalyzed by ANOVA with Tukey post-hoc test (p<0.05). Our results showed aproportional increase in the H/L index in concordance with CORT treatments. Thecrypt width significantly decreased in birds exposed to 80 mg/l of CORT.However, the other parameters did not show significant variation. In conclusionthe effect of CORT in the H/L index checks the effectiveness of the treatment.The decrease in the width of the crypts could be related to an effect at thelevel of enterocyte renewal. This fact may indicate the first event of a histologicalalteration in the intestine of Passerdomesticus. Supported by CyT-UNSL PROICO2-0516 and FONCYT PICT-201?0595.