Combination of BCAAs and glutamine enhances dermal collagen protein synthesis in protein-malnourished rats
Combination of BCAAs and glutamine enhances dermal collagen protein synthesis in protein-malnourished rats
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支链氨基酸和谷氨酰胺的组合可增强蛋白质营养不良大鼠的真皮胶原蛋白合成
作者：
H. Murakami;K. Shimbo;Y. Takino;Hisamine Kobayashi
在蛋白质营养不良的状态下，皮肤胶原蛋白会减少。氨基酸调节蛋白质代谢，谷氨酰胺通过转化为脯氨酸的过程刺激胶原合成，并提供成纤维细胞75%的细胞内游离脯氨酸。然而，在营养不良的情况下，这些氨基酸对胶原合成的影响还没有被研究。我们研究了氨基酸对蛋白质营养不良大鼠皮肤原胶原合成的影响。用L-[环-2H5]-苯丙氨酸掺入的方法评价各氨基酸和稳定同位素输注4h后真皮原胶原的合成分数(FSR，%/h)。12种单一氨基酸(谷氨酰胺、脯氨酸、丙氨酸、精氨酸、谷氨酸、甘氨酸、天冬氨酸、丝氨酸、组氨酸、赖氨酸、苯丙氨酸和苏氨酸)均不能显著增加FSR(P=0.343，单因素方差分析)。与生理盐水相比，必需氨基酸+谷氨酰胺+精氨酸(EAARQ)和支链氨基酸+谷氨酰胺(BCAAQ)的混合氨基酸显著增加了FSR，但支链氨基酸(BCAA)和胶原蛋白(AAC)的氨基酸混合物(AAC)对FSR无明显影响(生理盐水，0.96%±0.24%/h；EAARQ，1.76%±0.89%/h；BCAAQ，1.71%±0.36%/h；BCAAs，1.08%±0.20%/h，AAC 1.39±0.35%/h，P<；(0.05，图基测试)。用L-d7-脯氨酸和L-α-15N-谷氨酰胺预先恒定输注大鼠的实验结果表明，谷氨酰胺转化率仅为皮肤游离脯氨酸的3.9%。这些结果表明，BCAAQ的结合是促进蛋白质营养不良大鼠皮肤胶原合成的关键因素。与体外相比，细胞外游离谷氨酰胺对体内游离脯氨酸合成和胶原合成的贡献很小。
Skin collagen decreases in protein-malnourished states. Amino acids regulate protein metabolism, glutamine stimulates collagen synthesis through the conversion process to proline and provides 75 % of the intracellular free proline in fibroblasts. However, the impact of these amino acids on collagen synthesis under malnutrition has not been examined. We investigated the effect of amino acids on dermal tropocollagen synthesis in protein-malnourished rats. The fractional synthesis rate (FSR, %/h) of dermal tropocollagen was evaluated by the incorporation of l-[ring-2H5]-phenylalanine after 4 h infusion of each amino acid and the stable isotope. None of the infused 12 single amino acids (glutamine, proline, alanine, arginine, glutamate, glycine, aspartate, serine, histidine, lysine, phenylalanine and threonine) significantly increased the FSR (P = 0.343, one-way ANOVA). In contrast, amino acid mixtures of essential amino acids + glutamine + arginine (EAARQ) and branched-chain amino acids + glutamine (BCAAQ) significantly increased the FSR compared to saline, but the branched-chain amino acids (BCAAs) and amino acid mixture of collagen protein (AAC) did not alter the FSR (saline, 0.96 ± 0.24 %/h; EAARQ, 1.76 ± 0.89 %/h; BCAAQ 1.71 ± 0.36 %/h; BCAAs, 1.08 ± 0.20 %/h and AAC 1.39 ± 0.35 %/h, P < 0.05, Tukey’s test). Proline conversion from glutamine represented only 3.9 % of the free proline in skin, as evaluated by the primed-constant infusion of l-d7-proline and l-α-15N-glutamine in rats. These results suggested that the combination of BCAAQ is a key factor for the enhancement of skin collagen synthesis in protein-malnourished rats. The contribution of extracellular free glutamine on de novo proline synthesis and collagen synthesis is very low in vivo compared to the contribution in vitro.
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影响因子：
4.2
作者：
Anthony, JC;Anthony, TG;Jefferson, LS
通讯作者：
Jefferson, LS
影响因子：
2.2
作者：
Shi, HP;Fishel, RS;Barbul, A
通讯作者：
Barbul, A
DOI：
10.1016/j.bbrc.2003.07.014
发表时间：
2004-01-09
影响因子：
3.1
作者：
Kimball, SR;Jefferson, LS
通讯作者：
Jefferson, LS
影响因子：
7.1
作者：
Volpi, E;Kobayashi, H;Wolfe, RR
通讯作者：
Wolfe, RR
影响因子：
4.2
作者：
Crozier, SJ;Kimball, SR;Jefferson, LS
通讯作者：
Jefferson, LS