Plasma taurine concentrations increase after enteral glutamine supplementation in trauma patients and stressed rats.

BACKGROUND

Taurine is a unique amino acid with antioxidant and osmolytic properties. Glutamine serves as the preferred fuel for the gut, liver, and immune cells and as a precursor for antioxidants. Trauma patients have low glutamine concentrations.

OBJECTIVES

We investigated the effect of glutamine-enriched enteral nutrition on plasma taurine concentrations in patients with severe trauma (injury severity score >20). Additionally, plasma taurine concentrations and organ fluxes were studied in a stressed rat model.

DESIGN

Twenty-nine patients with multiple trauma received glutamine-enriched nutrition and 31 patients received isocaloric, isonitrogenous control solution for 5 d. Plasma taurine and glutamine concentrations were measured. Male Wistar rats (250-300 g) received a glutamine-enriched diet (12%, by wt) or a control solution for 2 wk. Plasma taurine concentrations were measured. Taurine fluxes and fractional extraction rates in the liver, kidneys, and gut were assessed with a radioactive microsphere technique.

RESULTS

Both patient groups had low taurine concentrations on day 1. From day 3 onward, the glutamine-fed patients had significantly higher taurine concentrations. Rats fed a glutamine-enriched diet had significantly higher plasma taurine concentrations than did the controls. A high taurine uptake was found in the liver, kidneys, and gut of the glutamine-fed rats. Fractional extraction rates were not significantly different between the rat groups.

CONCLUSIONS

Glutamine enrichment increases plasma taurine in trauma patients and in stressed rats. Because of increased availability, organ fluxes showed a higher taurine uptake in the liver, kidneys, and gut. The reduction in morbidity with glutamine enrichment could be explained in part by increased taurine availability.