GLUTATHIONE INVOLVEMENT ON THE INTESTINAL NA-DEPENDENT D-GLUCOSE ACTIVE TRANSPORTER()

Glutathione and its related enzymes are present in intestinal epitheli um. Depletion or alteration of glutathione levels have been related to different physiological and pathological conditions. Glutathione also seems to be related to the regulation of some protein activities. The present study, by in vivo experiments, shows a specific relationship between D-glucose Na+-dependent active transporter activity in rat int estine brush-border membranes and reduced glutathione/oxidized glutath ione ratio levels. Changes of the kinetic parameters show that an incr ease of this ratio is related to an increase of the affinity of glucos e for its binding sites and a higher transport capacity of the transpo rter. Neither alteration in the activity of other substrate transport systems nor change in the specific activity of the key enzymes related to glutathione and glucose metabolism are found. These findings sugge st the possibility that D-glucose transporter activity is modulated th rough the change in the redox status of glutathione.