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Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice.

Murakami H, Shimbo K, Inoue Y, Takino Y, Kobayashi H - Amino Acids (2011)

Bottom Line: The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice.Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30).However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively).

View Article: PubMed Central - PubMed

Affiliation: Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, 1-1 Suzuki-cho, Kawasaki, 210-8681, Japan. hitoshi_murakami@ajinomoto.com

ABSTRACT
Skin collagen metabolism abnormalities induced by ultraviolet (UV) radiation are the major causes of skin photoaging. It has been shown that the one-time exposure of UV irradiation decreases procollagen mRNA expression in dermis and that chronic UV irradiation decreases collagen amounts and induces wrinkle formation. Amino acids are generally known to regulate protein metabolism. Therefore, we investigated the effects of UV irradiation and various orally administered amino acids on skin collagen synthesis rates. Groups of 4-5 male, 8-week-old HR-1 hairless mice were irradiated with UVB (66 mJ/cm2) twice every other day, then fasted for 16 h. The fractional synthesis rate (FSR; %/h) of skin tropocollagen was evaluated by incorporating L-[ring-2H5]-phenylalanine. We confirmed that the FSR of dermal tropocollagen decreased after UVB irradiation. The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice. Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30). However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively). This result suggests that combinations of BCAA and glutamine or proline are important for restoring dermal collagen protein synthesis impaired by UV irradiation.

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Effect of UVB irradiation on the FSR of skin tropocollagen. Samples were irradiated with UVB one, two, three, or four times at one-day intervals. The FSR of tropocollagen decreased to its minimum value after two UVB irradiations. Values are means ± SD
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Fig2: Effect of UVB irradiation on the FSR of skin tropocollagen. Samples were irradiated with UVB one, two, three, or four times at one-day intervals. The FSR of tropocollagen decreased to its minimum value after two UVB irradiations. Values are means ± SD

Mentions: The FSR of skin tropocollagen tended to decrease after UVB irradiation, especially for mice that were irradiated twice with a one-day interval between irradiations (Fig. 2). The effect of orally administered amino acid on the FSR in the dermal tropocollagen of UVB-irradiated mice is shown in Fig. 3. Thirty minutes after oral amino acid administration, BCAA + Arg + Gln, BCAA + Gln, BCAA + Pro, and essential amino acids (EAA) significantly increased the FSR of skin tropocollagen compared with the control group (2.04 ± 0.54, 2.01 ± 0.50, 2.07 ± 0.59 and 2.07 ± 0.58%/h, respectively, in amino acid groups compared with DW, 1.47 ± 0.21%/h). However, single amino acids (Arg, Gln or Pro: 1.66 ± 0.39, 1.73 ± 0.67 or 1.45 ± 0.26%/h, respectively) and amino acid mixtures (BCAA, Arg + Gln or BCAA + Glu: 1.30 ± 0.32, 1.72 ± 0.26 or 1.74 ± 0.34, respectively) did not increase the FSR.Fig. 2


Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice.

Murakami H, Shimbo K, Inoue Y, Takino Y, Kobayashi H - Amino Acids (2011)

Effect of UVB irradiation on the FSR of skin tropocollagen. Samples were irradiated with UVB one, two, three, or four times at one-day intervals. The FSR of tropocollagen decreased to its minimum value after two UVB irradiations. Values are means ± SD
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3351609&req=5

Fig2: Effect of UVB irradiation on the FSR of skin tropocollagen. Samples were irradiated with UVB one, two, three, or four times at one-day intervals. The FSR of tropocollagen decreased to its minimum value after two UVB irradiations. Values are means ± SD
Mentions: The FSR of skin tropocollagen tended to decrease after UVB irradiation, especially for mice that were irradiated twice with a one-day interval between irradiations (Fig. 2). The effect of orally administered amino acid on the FSR in the dermal tropocollagen of UVB-irradiated mice is shown in Fig. 3. Thirty minutes after oral amino acid administration, BCAA + Arg + Gln, BCAA + Gln, BCAA + Pro, and essential amino acids (EAA) significantly increased the FSR of skin tropocollagen compared with the control group (2.04 ± 0.54, 2.01 ± 0.50, 2.07 ± 0.59 and 2.07 ± 0.58%/h, respectively, in amino acid groups compared with DW, 1.47 ± 0.21%/h). However, single amino acids (Arg, Gln or Pro: 1.66 ± 0.39, 1.73 ± 0.67 or 1.45 ± 0.26%/h, respectively) and amino acid mixtures (BCAA, Arg + Gln or BCAA + Glu: 1.30 ± 0.32, 1.72 ± 0.26 or 1.74 ± 0.34, respectively) did not increase the FSR.Fig. 2

Bottom Line: The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice.Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30).However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively).

View Article: PubMed Central - PubMed

Affiliation: Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, 1-1 Suzuki-cho, Kawasaki, 210-8681, Japan. hitoshi_murakami@ajinomoto.com

ABSTRACT
Skin collagen metabolism abnormalities induced by ultraviolet (UV) radiation are the major causes of skin photoaging. It has been shown that the one-time exposure of UV irradiation decreases procollagen mRNA expression in dermis and that chronic UV irradiation decreases collagen amounts and induces wrinkle formation. Amino acids are generally known to regulate protein metabolism. Therefore, we investigated the effects of UV irradiation and various orally administered amino acids on skin collagen synthesis rates. Groups of 4-5 male, 8-week-old HR-1 hairless mice were irradiated with UVB (66 mJ/cm2) twice every other day, then fasted for 16 h. The fractional synthesis rate (FSR; %/h) of skin tropocollagen was evaluated by incorporating L-[ring-2H5]-phenylalanine. We confirmed that the FSR of dermal tropocollagen decreased after UVB irradiation. The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice. Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30). However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively). This result suggests that combinations of BCAA and glutamine or proline are important for restoring dermal collagen protein synthesis impaired by UV irradiation.

Show MeSH
Related in: MedlinePlus