Guest guest Posted May 26, 2006 Report Share Posted May 26, 2006 Leucine is an amino acid, one of the branch-chain amino acids (BCAAs). Supplementation with BCAAs is popular among athletes and there is data indicating their ability to not only increase muscle mass with exercise but preserve it against wasting syndromes. Research also suggests that leucine is the key anti-catabolic BCAA, thus weightlifting (ie, anabolic) supplements are increasingly focusing on leucine. The following study looked to see what effect leucine has on protein synthesis in rats subjected to food-restriction-induced catabolism, essentially CR. The results match those observed in humans with wasting syndrome. Leucine supplementation seems to have preserved muscle mass vs controls. Also of note, there was no difference in the body weights of the two groups, but the controls had more fat. This suggests that leucine causes the body to spend fat and save muscle. Below the following study are some related studies. ~Ian Nutrition. 2006 May;22(5):520-7. Effects of leucine supplementation on the body composition and protein status of rats submitted to food restriction. OBJECTIVE: Acute administration of leucine has been shown to stimulate certain protein synthesis related anabolic processes. However, the effect of chronic leucine administration in a catabolic situation caused by food restriction (FR) has not been established. We therefore evaluated the effect of chronic leucine supplementation on the body composition and some indicators of protein nutritional status of rats submitted to FR. METHODS: Adult male Wistar rats were submitted to 50% FR for 6 weeks. The control group received the AIN-93M diet and the leucine group received the same diet supplemented with 5.91 g L-leucine/kg ration. We then determined carcass chemical composition, serum leptin, albumin and total protein concentrations, and protein, DNA and RNA concentrations in gastrocnemius muscle and liver. RESULTS: No difference in final body weight was observed between groups. However, the leucine group presented a lower amount of body fat (P < 0.05). Leptin concentration showed a directly proportional correlation with the amount of body fat (r = 0.88, P < 0.05), but no significant difference in serum leptin concentration was observed between groups (P = 0.08). Regarding protein nutritional status, liver protein concentration was higher in the leucine group (P < 0.05). In the gastrocnemius muscle, a higher RNA concentration (P < 0.05) and a tendency towards higher DNA concentration (P = 0.06) were observed in the leucine group. CONCLUSION: The results indicate that low-dose leucine supplementation increases body fat loss and improves liver protein status and the capacity of muscle protein synthesis in rats submitted to FR. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=16600817 Related studies: * Attenuation of the protein wasting associated with bed rest by branched-chain amino acids. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=10467608 * Leucine suppresses acid-induced protein wasting in L6 rat muscle cells. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=11422399 IAN: HMB (beta-hydroxy-beta-methylbutyrate) is a metabolite of leucine that has itself been shown to increase and preserve muscle mass against severe catabolic states. A few examples of the latter: * " These results suggest that HMB preserves lean body mass and attenuates protein degradation. " http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=15665304 * " CONCLUSION: These results show that HMB, arginine, and glutamine can be safely used to treat muscle wasting associated with AIDS and cancer. " http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=15080599 * Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\ ct & list_uids=10850936 http://iangoddard.net __________________________________________________ Quote Link to comment Share on other sites More sharing options...
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