PP088-MON GLUTAMINE SUPPLEMENTATION IMPROVES BODY WEIGHT RECOVERY AFTER METHOTREXATE TREATMENT IN RATS WHILE COMBINED GLUTAMINE AND ARGININE SUPPLEMENTATION INCREASES MORTALITY

Abstract

of nine amino acids on intestinal permeability during methotrexate (MTX) treatment in Caco-2 cells. Methods: Polarized Caco-2 cells were incubated in culture medium supplemented with glutamine, arginine, glutamate, leucine, taurine, citrulline, glycine, histidine or cysteine during 24 hours and then treated with MTX (100 ng/mL). The dose of each amino acid ranged from 15 to 20 fold the physiological plasma concentrations. Barrier function was assessed by Transepithelial electrical resistance (TEER), occludin and ZO-1 expression and localization. Results: Only glutamine, glutamate, arginine and leucine reversed the decrease of TEER observed after MTX treatment (p < 0.05). Interestingly, the addition of 6-diazo5-oxo-1-norleucine, a phosphate-dependent glutaminase inhibitor, blunted the effect of glutamine on MTXtreated cells (p < 0.05). We then evaluated the effects of glutamine, leucine and arginine combinations. Glutamine and arginine combination restored TEER to a similar extent than glutamine alone whereas other combinations were less effective. In addition, pretreatment of Caco-2 cells with glutamine and arginine, alone or in combination, prevented the decrease of ZO-1 and occludin expression (p < 0.05) and the alteration of their cellular distribution. Conclusion: Glutamine prevented MTX-induced barrier disruption in Caco-2 cells through its conversion into glutamate. Arginine also had protective effects but in a lesser extent.