Effect of starvation on the gastrointestinal tract in house sparrow (Passer domesticus)

FUNES SC; CHEDIACK, JG; CAVIEDES-VIDAL E

San Luis

Congreso; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2009

Sociedad de Biología de Cuyo

Starvation is a condition that often affects animals in nature (e.g. by unpredictable events such as storms). The gastrointestinal tract (GIT) is the first organ system that displays the most rapid and dramatic changes to nutrient deprivation. To date, little is known about the effect of starvation in the organ morphology and enzymatic function of the GIT in small passerine birds. Our objective is to determine the effect of starvation in the organ morphology (measuring mass of the digestive organs) and enzymatic function (measuring sucrase-isomaltase activity) in the gastrointestinal tract. To test our goal, ten Passer domesticus were acclimated to laboratory conditions with water and food ad libitum and then five animals were fasted by 34-36 hs (when loss body mass was more than 15%). The GIT was removed and organs (stomach, small intestine, liver and pancreas) weighed. Then, the small intestine was sectioned in three portions (proximal, medial and distal) and enterocytes were isolated for enzyme assays. Our results showed a significant reduction (between 25 to 50%) on all organs masses (ANOVA P < 0.005) in fasted birds, and a significant increase (̴150%) of the sucrase-isomaltase activity compared with controls (ANOVA P < 0.001).  While autophagy of digestive organs is induced by starvation, there is an up-regulation of sucrase-isomaltase activity in long-term fasting passerines birds to be ready for a refeeding.