Heat stress and its mitigation by capsaicin on digestive enzymes in house sparrows.

CACACE J; FERNÁNDEZ MARINONE G.; MANZANOS N; CID, FD; CHEDIACK, JG

San Luis

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

Sociedad de Biología de Cuyo

High temperature imposes severe stress on organisms.This stressful event predisposes to physiological disorders at differentlevels, modifying hematological parameters, as well as the activity ofdigestive functions or the proteins? expression (e.g. heat shock proteins) invertebrates, mainly in rats and poultry. Due to this negative effect of heatstress on animal health, nutritional research has begun to use additives in thediet to mitigate its effect. The aim of this work was to evaluate effect ofheat stress (increasing 10°C temperature) in the house sparrow and itsmitigation by capsaicin (an active component of chili peppers but not irritantin birds). To achieve our objective, 26 birds were kept in separate cages, withwater and food ad libitum and a light/dark photoperiod 12/12hs. Birdswere assigned to 4 independent treatments for 3 days: at 22°C without capsaicin(control), 22°C with capsaicin, 32°C without capsaicin and 32°C with capsaicin(control). Capsaicin was administered by gavage every day after lights on, at aconcentration of 31.25 x 10-3 mg*gr of body mass-1, incontrol groups gavage of water was performed. After treatment, body weightmeasure, blood extraction and subsequent removal of the intestine and pancreaswere performed at the same time (8:00 am), to avoid disturb by circadian/dailyvariation. We analyzed the data using a one-way and RM-ANOVA with Tukey post-hoctest (P<0.05). We observed an increased H/L ratio during heat stress (P<0.01),and it was reverted when capsaicin was administered (P<0.01). Heat stressproduces a decrease in the intestinal mass (P´s<0.05) but no changes wereobserved in activity of digestive enzymes: maltase, sucrase, aminopeptidase,trypsin and chymotrypsin in all treatments under heat stress and capsaicinadministrations (P´s > 0.1). Studies in chickens and rats show that avariation in 10°C produces stress, but there are a controversial results abouteffect of heat stress and capsaicin administration on modulation of intestinaland pancreatic enzymes. However, in both cases, capsaicin proved to bestress-relieving compound. In our case, in wild birds we found a mitigation ofheat stress by capsaicin, but we didn´t found effect on digestive enzymeactivities, in spite of effect of heat stress on the intestinal mass. Future research will be in direction tocomparative studies in poultry and wild birds, under the same experimentaldesign, to dilucidated mechanism involved in enzyme modulation. Supportedby CyT-UNSL PROICO 2-0516 and FONCYT PICT-201?0595.