Nonetheless, in the physiological condition, that is, during meal absorption, in order for dietary amino acids to reach the systemic circulation and be made available for the muscle tissue, they have to pass through the splanchnic tissues. It is well known that the splanchnic tissues in young individuals use a significant portion of the dietary amino acids for their own metabolism (). It has been also demonstrated that the first-pass splanchnic extraction of leucine increases with age (). Thus, if the splanchnic tissues utilized more amino acids in the elderly, the flow and availability of dietary amino acids for the peripheral tissues, including muscle, would be reduced; hence the response of muscle protein anabolism to a given dose of amino acids would be blunted. To test this hypothesis, we compared the response of muscle protein metabolism to the oral administration of a large dose of mixed amino acids in young and elderly subjects using stable isotope methodologies to measure the parameters of muscle protein metabolism (). Interestingly, despite a higher phenylalanine first-pass splanchnic extraction in the elderly, we found that the delivery of amino acid to the leg increased to the same extent in both the young and elderly. Additionally, amino acid transport into the muscle, its utilization for protein synthesis, the mixed muscle protein fractional synthetic rate, and the net protein balance increased significantly and similarly in both age groups (). Thus, from these data we concluded that although the splanchnic first-pass extraction of oral amino acids increases with age, it does not prevent the dietary amino acids from reaching the systemic circulation and stimulating net muscle protein anabolism in the elderly as it does in the young. It is likely that the higher amino acid first-pass splanchnic extraction in older subjects is more a reflection of a higher splanchnic turnover rate (i.e., higher synthesis and breakdown) rather than of an isolated higher splanchnic utilization rate for synthesis and oxidation such that splanchnic net balance of amino acid is similar between young and old subjects during meal absorption.
2- Rapid penetration within the plant as a result of presence ofIron mixed on Amino Acids subsequently it helps the plant toovercome unfavorable harsh conditions quickly.