Resumen de Leptin effect on galactose absorption in mice jejunum.

J. Barrenetxe, Ana María Barber Cárcamo, María Pilar Lostao Crespo

• Previous studies from our laboratory show that leptin inhibits sugar absorption in rat small intestine. In this work, the effect of the hormone on galactose absorption in mice jejunum is characterized. The experimentes were carried out in vitro by using everted jejunal rings. Leptin inhibits galactose uptake by the rings depending on the concentration of the hormone (0.20-78 nM) and time exposure. Maximal inhibition is obtained at 7.8 nM (2 min incubation) and at 0.39 nM (30 min). Leptin does not affect non mediated sugar uptake (measured in the presence of 1 mM phloridzin), indicating that hormone only alters SGLT1. Kinetic studies demonstrate that leptine increases the apparent affinity constant of the galactose transport without modifying the Vmax value. On the whole, the results indicate that leptin inhibits intestinal galactose absorption in mouse by decreasin affinity of SGLT1 for the sugar.