PANCREATIC ENZYME ACTIVITY IN Passer domesticus EXPOSED TO CORTICOSTERONE

PADRONES MN; CID F.; CHEDIACK, JG

San Luis

Congreso; XXIX Reunion Anual de la Sociedad de Biología de Cuyo; 2021

Sociedad de Biología de Cuyo

In animals, it is well documented that stress produces metabolicalterations and an allostatic response (activation of thehypothalamic-pituitary-adrenal axis and increase of corticosterone levels inblood) to maintain homeostasis in organisms. The objective of this work was tostudy the long-term corticosterone (CORT) effects on the digestive function in Passer domesticus. We focus especiallyon modifications in the activity of pancreatic enzymes, trypsin andchymotrypsin. To achieve our goal, 32 sparrows were exposed to differentconcentrations of CORT in drinking water (0, 20, 40 and 80 mg/l) for 72 hoursemulating a long-term stress situation. After treatment, body weight was measured,blood extraction and subsequent removal of digestive organs (intestine, liverand pancreas) were performed at the same time (8:00 am), to avoid disturb bycircadian/daily variation. The Heterophil/Lymphocyte (H/L) ratio was used as anindicator of stress in birds. The mass of pancreas was measured andhomogenized. The enzymatic activity of trypsin and chymotrypsin weredetermined. Previously, chymotrypsinogen was activated by enterokinase for 60min to measure chymotrypsin activity. We analyzed the mass-specific enzyme activities (μmol min−1 gwet tissue−1) using one-way ANOVA with Tukey post-hoc test(p<0.05). We found a proportional increased in the H/L index in concordancewith CORT treatments. It was not found differences in the mass of pancreas andactivity of enzymes (p>0.05). Studies in chickens show a variation in digestiveenzymes by corticosterone. However, our case in wild birds, we didn´t foundeffect of CORT on pancreatic enzyme activities. Previously, we found similarresults with intestinal enzymes (carbohydrases and proteases). So, futureresearch will be in direction to comparative studies in poultry and wild birds,under the same experimental design, to dilucidated mechanism involved in enzymemodulation by CORT. Supported by CyT-UNSLPROICO 02-0820 and FONCYT PICT-201?0595.