caa a22 4500 38806272X CHVBK 20180307125125.0 cr unu---uuuuu 161130e199805 xx s 000 0 eng 10.1079/BJN19980074 doi S0007114598000750 pii (NATIONALLICENCE)cambridge-10.1079/BJN19980074 Drug-nutrient interactions: inhibition of amino acid intestinal absorption by fluoxetine [Elektronische Daten] Fluoxetine is one of the most widely used antidepressants and nowadays it is also being used to manage obesity problems. In our laboratory we demonstrated that the drug inhibited sugar absorption (Monteiro et al. 1993). The aim of the present work was to determine the effect of fluoxetine on intestinal leucine absorption. Using a procedure of successive absorptions in vivo the drug diminished amino acid absorption by 30% (P < 0.001). Experiments in vitro in isolated jejunum also revealed a reduction in leucine uptake of 37% (P < 0.001). In both cases fluoxetine only affected mediated transport without altering diffusion. In a preparation enriched in basolateral membrane, fluoxetine inhibited the Na+,K+-ATPase (EC 3.6.1.37) activity (55%; P < 0.001) in a non-competitive manner with an inhibition constant (Ki) value of 0.92 mm. Leucine uptake by brush-border membrane vesicles was diminished by the drug (a reduction of 48% was observed at 30s, P < 0.001); only the apical Na+-dependent transport system of the amino acid was modified and the inhibition was non-competitive. Leucine uptake in the presence of lysine indicated that transporter B was involved. These results suggest that fluoxetine reduces leucine absorption by its action on the basolateral and apical membrane of the enterocyte; the nutritional status of the patients under drug treatment may be affected as neutral amino acid absorption is decreased. Copyright © The Nutrition Society 1998 Fluoxetine nationallicence Drug-nutrient interactions nationallicence Intestinal absorption nationallicence Urdaneta Elena Departamento de Fisiología y Nutrición, Universidad de Navarra, C/Irunlarrea s/n, 31008 Pamplona, Spain Idoate Isabel Departamento de Bioquímica, Hospital Virgen del Camino, C/Irunlarrea no. 4, 31008 Pamplona, Spain Larralde Jesús Departamento de Fisiología y Nutrición, Universidad de Navarra, C/Irunlarrea s/n, 31008 Pamplona, Spain British Journal of Nutrition Cambridge University Press 79/5(1998-05), 439-446 0007-1145 79:5<439 1998 79 BJN https://doi.org/10.1079/BJN19980074 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1079/BJN19980074 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Urdaneta Elena Departamento de Fisiología y Nutrición, Universidad de Navarra, C/Irunlarrea s/n, 31008 Pamplona, Spain NATIONALLICENCE 700 1- Idoate Isabel Departamento de Bioquímica, Hospital Virgen del Camino, C/Irunlarrea no. 4, 31008 Pamplona, Spain NATIONALLICENCE 700 1- Larralde Jesús Departamento de Fisiología y Nutrición, Universidad de Navarra, C/Irunlarrea s/n, 31008 Pamplona, Spain NATIONALLICENCE 773 0- British Journal of Nutrition Cambridge University Press 79/5(1998-05), 439-446 0007-1145 79:5<439 1998 79 BJN CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge