Citat:
Ursprungligen postat av Sverker
Undantaget är de 2 - 5 g som du kan bygga in som ny muskelmassa på ett dygn.
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Nja, mer än så är det allt. Proteinnedbrytningen uppgår till många gram per dygn, och så även proteinsyntesen. Det är protein
balansen som kan bli positiv i storleksordningen av dom där 2 -5 grammen, men mycket mer byggs in som muskelprotein. Bara efter träning, vid intag av EAA byggs cirka 25% av dessa in som muskelprotein:
"The estimated nitrogen uptake across both legs can be estimated by calculating the ratio of phenylalanine uptake across both legs and the amount of phenylalanine contained in the drink. The area under the curve for phenylalanine net balance across both legs was calculated for 3 h after ingestion of the EAA drink given 1 h postexercise. The total amount of phenylalanine taken up was ~21-26% of the total amount of phenylalanine in the drink. If we assume that this ratio is consistent for all essential amino acids in the drink and if we know that the EAA drink contains ~827 mg of nitrogen, then we can calculate that ~211 mg of nitrogen were taken up by the legs during the 3 h after ingestion of the drink."
Considering that the first-pass splanchnic bed extracts 30% of the ingested phenylalanine, it appears that of the amino acids that actually enter the bloodstream a very high proportion are being specifically taken up by the legs. Furthermore, the lack of an increase in either alanine or urea production after the drink supports the conclusion that amino acids are incorporated into protein, as opposed to being catabolized."
J Appl Physiol. 2000 Feb;88(2):386-92.
Och allt fenylalanin som tas upp i muskeln byggs in som muskelprotein:
"Phenylalanine is not oxidized in the muscle, so the only metabolic fate for phenylalanine taken up by the muscle is for protein synthesis. The muscle intracellular pool of phenylalanine at the end of sampling was the same as at baseline, and net phenylalanine balance had returned to baseline levels by the end of sampling, indicating that sampling accounted for the entire response to the ingested protein. Thus, it can be assumed that all the phenylalanine taken up by the muscle was utilized for muscle protein synthesis."
Med Sci Sports Exerc. 2004 Dec;36(12):2073-81.