Glutamate reduces experimental intestinal hyperpermeability and facilitates glutamine support of gut integrity

Figure 1 Model illustrating intestinal cell lineage with tight junctions and EAAT transporter. The extracellular enzymatic conversion of glutamine to glutamate by γ-glutamyltransferase (γ-GT) is shown on the apical side. The experimental design of the study using the γ-GT blocking enzyme, acivicin, and the blocker of the glutamate transporter, EAAT L-trans-pyrrolidine-2,4-dicarboxylic, is included in the figure.

Figure 2 Effects of glutamine and glutamate on phorbol-12,13-dibutyrate-induced permeability in the two intestinal cell lines. A: In the HT29Cl.19A cell line, glutamine addition resulted in a 45% decrease in permeability. Acivicin nullified this effect, n = 6; B: In the Caco2.BBE cell line, glutamine addition resulted in a 30% decrease in permeability, n = 3; C: In the HT29Cl.19A cell line, glutamate addition resulted in a 25% decrease in permeability, n = 3; D: In the Caco2.BBE cell line, glutamate addition resulted in a 25% decrease in permeability. Trans-PDC nullified this effect, n = 4. ^aP < 0.05, ^bP < 0.01, ^cP < 0.01.