Glutamine Metabolism in Lymphoid Tissues
When lymphocytes are suitably stimulated either specifically (by an antigen) or non-specifically (by mitogens), they are transformed into a state of high biochemical activity which initiates production of various mediators of immunity including antibodies if they are B-lymphocytes and the mediators of cellular immunity (e.g., lymphotoxin, chemotactic factors, mitogenic factors) if they are T-lymphocytes. To perform this activity lymphocytes require an increased rate of ATP generation and it has generally been assumed that glucose was the only quantitatively important fuel (see Hume and Weidemann 1980). Recently Ardawi and Newsholme (1982) have provided evidence to suggest that other fuels can be utilised by lymphocytes. This suggestion is based on the maximal activities of key enzymes of the energy-producing pathways in lymphocytes, the ability of these cells to utilise glutamine, ketone bodies (3-hydroxybutyrate and acetoacetate) and long-chain fatty acids (oleate and palmitate) (Table 1) and the effects of these fuels on oxygen consumption by lymphocytes. Of these fuels glutamine may be quantitatively the most important.
KeywordsGlutamate Dehydrogenase Glutamine Metabolism Oleate Acetate Oxoglutarate Dehydrogenase Glutamine Transport
Unable to display preview. Download preview PDF.
- Ardawi MSM (1983) Some aspects of energy metabolism in lymphocytes. D Phil Thesis, Univ OxfordGoogle Scholar
- Ardawi MSM, Newsholme EA (1984b) Glutamine transport into lymphocytes. Biochem J (submitted)Google Scholar
- Garber AJ (1980) Glutamine metabolism in skeletal muscle. In: Mora J, Palacios R (eds) Glutamine metabolism, enzymology and regulation. Academic Press, London New York, pp 259–284Google Scholar
- Goldstein L (1976) Ammonia production and excretion in the mammalian kidney. In: Thurau K (ed) Int Rev Physiol (Kidney and urinary tract physiology II), vol XI. Univ Park Press, Baltimore, pp 283–316Google Scholar
- Hanson PJ, Parsons DS (1978) Factors affecting the utilisation of ketone bodies and other substrates by rat jejunum: effects of fasting and of diabetes. J Physiol (London) 278: 55–67Google Scholar
- Hume DA, Weidemann MJ (1980) Mitogenic lymphocyte transformation. Elsevier/North Holland, AmsterdamGoogle Scholar
- Krebs HA (1980) Glutamine metabolism in the animal body. In: Mora J, Palacios R (eds) Glutamine metabolism, enzymology and regulation. Academic Press, London New York, pp 319–329Google Scholar
- Newsholme EA, Leech AR (1983) Biochemistry for the medical sciences. Wiley, London New YorkGoogle Scholar
- Newsholme EA, Start C (1973) Regulation on metabolism. Wiley, London New YorkGoogle Scholar
- Tate SS, Meister A (1978) Glutamine synthetases of mammalian liver and brain. In: Prusiner S, Stadtman ER (eds) The enzymes of glutamine metabolism. Academic Press, London New York, pp 77–125Google Scholar