Effect of starvation in sucrase-isomaltase expression in Passer domesticus

FUNES SC; CHEDIACK, JG; GATICA SOSA CP; CAVIEDES-VIDAL E

Mendoza

Congreso; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2010

Sociedad de Biología de Cuyo, CyT UN de Cuyo y CyT Ministerio de Salud del Gobierno de Mendoza

Effect of starvation in sucrase-isomaltase expression in Passer domesticus Funes, SC, Chediack JG, Gatica Sosa, CP, Caviedes-Vidal E. Laboratorio de Biología Integrativa – IMIBIO-SL. CONICET. UNSL. San Luis. E-mail samanta.funes@gmail.com Starvation often affects animals in nature being gastrointestinal tract the first organ system that displays faster and dramatic changes to nutrient deprivation. To date, little is known about the effect of long starvation (phase III) on the digestive functions (i.e. enzyme expression) in small passerine birds. Our objective was to determine the effect of starvation in the expression (activity and mRNA abundance) of sucrase-isomaltase (SI). To test our goal, eight Passer domesticus were acclimated to laboratory conditions with water and food ad libitum, then four animals were fasted around 34 hs (phase III of starvation). The small intestines were removed and sectioned in three portions (proximal, medial and distal) and enterocytes were isolated for enzyme assays and total RNA extraction. The RT-PCR was achieved with a specific primer designed in our laboratory for SI gene of house sparrow using GAPDH as reference gene. We found a significant increase of the SI activity (~150% ANOVA P < 0.001) and Vmax of the enzyme (P < 0.02) in fasted animals compared with controls; however there was not a significant increase in the mRNA of SI (p > 0.55). We concluded that it could be involved a post-transcriptional up-regulation of SI expression in long-term fasted passerine birds. Supported by FONCYT (PICT 2007 Nº 1320) and CyT-UNSL 9502 to ECV, and PIP N° 11220090100998 CONICET and CyT-UNSL 0110 to JGC.