Glutamine or Ornithine Alpha-Ketoglutarate


Glutamine or Ornithine Alpha-Ketoglutarate

Glutamine is the most abundant free amino acid in human muscle and plasma, is utilized at high rates by rapidly dividing cells including your immune system, and provides energy and optimal conditions for RNA and DNA biosynthesis.( 1) Six amino acids are metabolized (made) in resting muscle. They are leucine, isoleucine, valine, asparagine, aspartate and glutamate. These amino acids provide the amino groups for synthesis of other amino acids such as glutamine and alanine.( 2)

The actual biochemistry is complicated. We'll try to explain it simply. Glutamate plus adenosine triphosphate (ATP) and ammonia are required to make glutamine.( 3) For this process glutamine acts as an ammonia scavenger. Alpha-ketoglutarate and ammonia (plus a few other chemicals) are required to make glutamate. Alpha-ketoglutarate then combines with glutamine breaking it down into glutamate again. This building-up and breaking-down process donates nitrogen and removes ammonia. Glutamate with the help of alpha-ketoglutarate is also involved in the formation of two other amino acids, proline and arginine.

The most important part of this metabolic process is the use of ammonia to combine with alpha-ketoglutarate to first form glutamate, and then to form glutamine from glutamate, ATP and ammonia. These processes keep the levels of ammonia in your system down. This formation of glutamine is also important because of protein synthesis. Glutamine carries two nitrogen molecules and can transport nitrogen and nitrogen waste.( 4)

So how does this complicated biochemistry affect what we use as athletes? Many recent studies have shown us that glutamine is an important amino acid. During various catabolic states including surgical trauma, infection, starvation and prolonged exercise, glutamine is placed under stress and plasma glutamine levels fall.( 1) During intense exercise both glutamate and glutamine levels fall, as do other amino acid levels, as a process of deamination occurs in the liver.( 5)

Companies quick to catch onto this research are now touting glutamine supplements. Glutamine is involved in protein synthesis and it will work, but by taking large amounts of glutamine supplements you are bypassing the formation process of glutamine and the uptake of free ammonia. You are also adding extra ammonia back into the system when the glutamine is broken down.

This problem is easily overcome by the use of ornithine alpha-ketoglutarate. By adding to your stores of alpha-ketoglutarate you are adding one of most important links to the formation of glutamate and glutamine and are lessening your ammonia burden. A recent study conducted in France concluded that the use of ornithine alpha-ketoglutarate significantly improved nitrogen balance and was associated with a gradual rise in plasma glutamine.( 6)

As we have written before, ornithine alpha-ketoglutarate solves many problems. It provides the raw material for glutamate and glutamine and it does not add to your ammonia burden. In fact, it works as an ammonia scavenger. It also increases insulin and promotes growth. One study conducted on children with growth retardation concluded that OKG increased insulin-like growth factor 1 (IGF1) and glutamine and glutamate levels.( 8) Glutamine on its own can't do this.

In summary, ornithine alpha-ketoglutarate provides a strong releaser of growth hormone, a ready source of glutamate and glutamine, is an anti-catabolic, a big stimulus to the insulin drive, a source of arginine, a support for the immune system and is an ammonia scavenger.( 7) Any athlete who uses just glutamine is giving away a potent edge.

(1.) Walsh NP et al. Glutamine, exercise and immune function. Links and possible mechanisms. Sports Med, 1998;26:177-191.

(2.) Wagenmakers AJ. Muscle amino acid metabolism at rest and during exercise: role in human physiology and metabolism. Exer Sport Sci Rev, 1998;26:287-314.

(3.) Stryer L. Biochemistry, 2nd Ed. New York, NY: W. H. Freeman and Company, 1981.

(4.) Roth E, et al. Glutamine; Anabolic effector? J Parent Ent Nutr, 1990; 14:1305-1365.

(5.) Van Hall G, et al. Deamination of amino acids as a source for ammonia production in human skeletal muscle during prolonged exercise. J Physiol, 1995;489:251-261.

(6.) De Bandt JP, et al. A randomized controlled trial of the influence of the mode of enteral ornithine alpha-ketoglutarate administration in burn patients. J Nutr, 1998;128:563-569.

(7.) Colgan M. Optimum Sports Nutrition. New York , NY: Advanced Research Press, 1993.

(8.) Moukarzel AA, et al. Growth retardation in children receiving long-term total parenteral nutrition: effects of ornithine alpha-ketoglutarate. Amer J Clin Nutr, 1994;60:408-413.

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