New study on BCAA

[Beast]

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_DocSum

J Nutr. 2006 Feb;136(2):529S-32S. Related Articles, Links

Nutraceutical effects of branched-chain amino acids on skeletal muscle.

Shimomura Y, Yamamoto Y, Bajotto G, Sato J, Murakami T, Shimomura N, Kobayashi H, Mawatari K.

"BCAA catabolism in skeletal muscle is regulated by the branched-chain alpha-keto acid dehydrogenase (BCKDH) complex, located at the second step in the BCAA catabolic pathway. The activity of the BCKDH complex is regulated by a phosphorylation/dephosphorylation cycle. Almost all of BCKDH complex in skeletal muscle under normal and resting conditions is in an inactive/phosphorylated state, which may contribute to muscle protein synthesis and muscle growth. Exercise activates the muscle BCKDH complex, resulting in enhanced BCAA catabolism. Therefore, exercise may increase the BCAA requirement. It has been reported that BCAA supplementation before exercise attenuates the breakdown of muscle proteins during exercise in humans and that leucine strongly promotes protein synthesis in skeletal muscle in humans and rats, suggesting that a BCAA supplement may attenuate muscle damage induced by exercise and promote recovery from the damage. We have examined the effects of BCAA supplementation on delayed-onset muscle soreness (DOMS) and muscle fatigue induced by squat exercise in humans. The results obtained showed that BCAA supplementation prior to squat exercise decreased DOMS and muscle fatigue occurring for a few days after exercise. These findings suggest that BCAAs may be useful for muscle recovery following exercise."

[doogieh]

Is this from the same issue as Layne's article? I'll have to make a point of stopping by the Med Library.

What BCAA dose was used in this study?

[Phosphate bond]

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

this is current also. Actually I have a few more as well.

"We also evaluated changes of fractional synthesis rate (FSR) of skeletal muscle protein during infusion of leucine alone or EAAs for 4 h in anesthetized normal rats. FSR showed a transient increase at 15-30 min of leucine infusion and then declined, whereas FSR stayed elevated throughout EAA infusion."

Of course we all know that Leucine is part of the Essential amino acid family.

[Phosphate bond]

Originally Posted by Beast

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_DocSum

J Nutr. 2006 Feb;136(2):529S-32S. Related Articles, Links

Nutraceutical effects of branched-chain amino acids on skeletal muscle.

Shimomura Y, Yamamoto Y, Bajotto G, Sato J, Murakami T, Shimomura N, Kobayashi H, Mawatari K.

"BCAA catabolism in skeletal muscle is regulated by the branched-chain alpha-keto acid dehydrogenase (BCKDH) complex, located at the second step in the BCAA catabolic pathway. The activity of the BCKDH complex is regulated by a phosphorylation/dephosphorylation cycle. Almost all of BCKDH complex in skeletal muscle under normal and resting conditions is in an inactive/phosphorylated state, which may contribute to muscle protein synthesis and muscle growth. Exercise activates the muscle BCKDH complex, resulting in enhanced BCAA catabolism. Therefore, exercise may increase the BCAA requirement. It has been reported that BCAA supplementation before exercise attenuates the breakdown of muscle proteins during exercise in humans and that leucine strongly promotes protein synthesis in skeletal muscle in humans and rats, suggesting that a BCAA supplement may attenuate muscle damage induced by exercise and promote recovery from the damage. We have examined the effects of BCAA supplementation on delayed-onset muscle soreness (DOMS) and muscle fatigue induced by squat exercise in humans. The results obtained showed that BCAA supplementation prior to squat exercise decreased DOMS and muscle fatigue occurring for a few days after exercise. These findings suggest that BCAAs may be useful for muscle recovery following exercise."

Personally I think metabolizing BCAAs probably has beneficial effects on the energy metabolism of the athlete as a "whole"

If you wanted to test this I guess you could knock out Branched chain alpha keto acid dehydrogenase with and without supplementation and see what happened?

I'm guessing blocking the catabolism of BCAAs (for example during fat oxidation) would do more harm than good. That's the benefit of supplementation though....you can just replace losses without disturbing normal metabolic processes that may in fact be "protective" and/or "beneficial"

[Beast]

Originally Posted by Phosphate bond

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

this is current also. Actually I have a few more as well.

"We also evaluated changes of fractional synthesis rate (FSR) of skeletal muscle protein during infusion of leucine alone or EAAs for 4 h in anesthetized normal rats. FSR showed a transient increase at 15-30 min of leucine infusion and then declined, whereas FSR stayed elevated throughout EAA infusion."

Of course we all know that Leucine is part of the Essential amino acid family.

I wish they would have done leucine vs. BCAA vs. EAA.

One possibility for the decline in FSR when leucine was administered alone could be the depletion of isoleucine and valine, which would halt protein synthesis. Administering BCAA (as I have been suggesting) or EAA instead of just leucine would prevent this from happening.

[Beast]

Originally Posted by Phosphate bond

Personally I think metabolizing BCAAs probably has beneficial effects on the energy metabolism of the athlete as a "whole"

If you wanted to test this I guess you could knock out Branched chain alpha keto acid dehydrogenase with and without supplementation and see what happened?

I'm guessing blocking the catabolism of BCAAs (for example during fat oxidation) would do more harm than good. That's the benefit of supplementation though....you can just replace losses without disturbing normal metabolic processes that may in fact be "protective" and/or "beneficial"

I agree that blocking BCAA metabolism would not be a good idea.