Disaccharidases in the subterranean rodent Ctenomys talarum: relation to energetic cost of reproduction

DEL VALLE, J.C.; LOPEZ MAÑANES A.A.

Córdoba, Argentina,

Congreso; First Meeting of Argentine Biology Societies.; 2007

Sociedades Argentinas de Biología

Pregnancy and lactancy are energetically expensive periods for C. talarum. The aim of this work was to determine the relationship between disaccharidases activities and the energy cost of reproduction. Sucrase and maltase activities were determined in small intestine of C. talarum captured in Mar de Cobo (Bs. As., Argentine). 13000xg supernatants were used as enzyme extract (homogenization medium: 0.15 M NaCl) (20 mL g-1 of tissue). Activities were assayed by a colorimetric method (sucrase or maltase 28 mM in 0.1 M maleate/OHNa pH 6.5 at 37°C. Reproductive females exhibited lower sucrase and maltase activities than non-reproductive ones (t=2.8 df=8 p< 0.0021). No differences were found between males in different reproductive status (p>0.05). In reproductive females maltase activity appeared to be accounted for the sucrase-isomaltase complex (maltase= -35.23±7.74 x sucrase; r=0.92, p<0.0025), but it was independent of sucrase–isomaltase complex activity (p>0.05) in non-reproductive females, immature and mature males. Our results show the occurrence of qualitative changes of disaccharidases activities in females of C. talarum in relation to increased energy demands upon pregnancy and lactancy.