Glutamine effects on permeability and ATP content of jejunal mucosa in starved rats

Starvation induces an increase in intestinal permeability that can be of importance to intestinal integrity. Glutamine is the principal energy source for intestinal enterocytes and is considered essential for gut metabolism, structure and function. The aim of this study was to investigate whether glutamine could improve the ATP content of the mucosa of starved rats and attenuate the permeability perturbation during incubation in vitro in Ussing chamber.

Segments of jejunum from rats starved for 48 h were mounted in Ussing chambers. Glutamine was added to Krebs-buffer at 0.6mM, 3mM, 6mM and 30mM concentrations on the mucosal side. Cr-EDTA permeation, ATP content of the epithelium mucosa and electrophysiology were studied during 180 min of incubation in Ussing chambers.

These was a negative linear correlation between ATP content and(51)Cr-EDTA permeability in stripped mucosa. ATP content was reduced in all groups during the experiment. When 30 mM glutamine was added on the mucosal side there was an increase in(51)Cr-EDTA permeability (P< 0.001). There was no effect of glutamine on transepithelial resistance but higher concentrations of glutamine (>3mM) significantly increased the short circuit current.

Supplementing glutamine to the mucosal side in the Ussing chamber led to an increase in ion pump activity and to an increase in paracellular permeability at the 30mM glutamine concentration. Glutamine did not restore the intracellular ATP level. The increase in permeability was inversely correlated to the mucosal ATP content.