The Royal Society of Medicine

Glutamine is a five-carbon neutral aminoacid containing two carboxyl groups one of which is bound to nitrogen, forming an amide group. It is the most abundant free aminoacid in the body.1 In the extracellular fluid it constitutes about 25% of the free aminoacid pool, in skeletal muscle more than 60%.1 A healthy 70 kg man contains 80 g of glutamine and the concentration of glutamine in his blood is 500– 700 mmol/L. Glutamine has numerous functions in normal physiol-ogy—for example, it acts as a precursor for protein synthesis; it provides the nitrogen for synthesis of arginine, purines, pyrimidines, nucleotides, glutathione and taurine (the last two being important antioxidants); and it transports amino-nitrogen to intestine, liver and kidney.1–3 With its involvement in renal ammoniagenesis it play