Post by str8flexed on Nov 18, 2004 12:04:11 GMT -5
unfortunately, not much glutamine makes it into the bloodstream from oral supplementation. When glutamine enters the small intestine and is absorbed into the mucosal cell, it is then metabolized via brush boarder enzymes to two different products. One product is alanine which is created from the alpha nitrogen on glutamine, the other product is the carbon skelaton left over with the epsilon nitrogen. This carbon skelaton is then oxidized by the gut for fuel while the ammonia group is excreted, or may enter the urea cycle. The alanine from this process is sent to the liver via the portal vein where it is used to form glucose via gluconeogenesis. It is in this way that our body prevents us from overloading ourselves with individual amino acids. The liver and mucosal cells act as a buffer to the peripheral tissues. If this buffer wasn't in place it could have dire health consequences. So to recap, you can't overload yourself with certain amino acids, b/c before ANY nutrient that is orally administered enters the blood stream, it has to pass by the liver, and since the liver regulates amino acid levels, if it "sees" that things may get out of wack it will retain these substrates for gluconeogenesis (making glucose from amino acids) which it will then pass on to the peripheral tissues.
It takes a very large bolous dose to get glutamine past the gut in any appreciable amount. Above 35g will result in a 50% absorption. Even so, the liver will metabolize the rest of this glutamine as this same study by Wolfe from U of Texas where he should a bolous dose could result in 50% absorption.. intracellular levels of glutamine did not change... indicating to me that the liver took care of the rest.
All the studies that show glutamine increases LBM have 3 problems with them
1) they are done using IV. Of course this will work b/c you bypass the gut using an IV
2) the control groups are not consuming anything at all. Hmm gee if I give NO FOOD compared to glutamine... of course glutamine will be better, but a comparative amount of whole protein would do the same thing, or would be better
3) The subjects are in a diseased state. Diseased states are associated (especially HIV and cancer, which is what alot of these glutamine studies use) with gut atrophy. Since glutamine is the main fuel for the gut... glutamine will increase gut tissue size. Thus the increase in lean body mass is NOT due to an increase in skeletal muscle, but rather an increase in the smooth muscle size of the gut.
Now if you have a gut atrophy disease such as celiac's, crohn's etc, then taking glutamine during flair ups is a GREAT idea. But to try to sell it as a muscle growth agent is fraudulent, deceiving, and a misrepresentation of the scientific data.
-Layne
It takes a very large bolous dose to get glutamine past the gut in any appreciable amount. Above 35g will result in a 50% absorption. Even so, the liver will metabolize the rest of this glutamine as this same study by Wolfe from U of Texas where he should a bolous dose could result in 50% absorption.. intracellular levels of glutamine did not change... indicating to me that the liver took care of the rest.
All the studies that show glutamine increases LBM have 3 problems with them
1) they are done using IV. Of course this will work b/c you bypass the gut using an IV
2) the control groups are not consuming anything at all. Hmm gee if I give NO FOOD compared to glutamine... of course glutamine will be better, but a comparative amount of whole protein would do the same thing, or would be better
3) The subjects are in a diseased state. Diseased states are associated (especially HIV and cancer, which is what alot of these glutamine studies use) with gut atrophy. Since glutamine is the main fuel for the gut... glutamine will increase gut tissue size. Thus the increase in lean body mass is NOT due to an increase in skeletal muscle, but rather an increase in the smooth muscle size of the gut.
Now if you have a gut atrophy disease such as celiac's, crohn's etc, then taking glutamine during flair ups is a GREAT idea. But to try to sell it as a muscle growth agent is fraudulent, deceiving, and a misrepresentation of the scientific data.
-Layne