Rathor, Richa, Sukanya Srivastava, and Geetha Suryakumar. A comparative biochemical study between L-carnosine and β-alanine in amelioration of hypobaric hypoxia-induced skeletal muscle protein loss. High Alt Med Biol 00:000-000, 2023. Background: Carnosine (CAR; β-alanyl-L-histidine), a biologically active dipeptide is known for its unique pH-buffering capacity, metal chelating activity, and antioxidant and antiglycation property. β-Alanine (ALA) is a nonessential amino acid and used to enhance performance and cognitive functions. Hypobaric hypoxia (HH)-induced muscle protein loss is regulated by multifaceted signaling pathways. The present study investigated the beneficial effects of CAR and ALA against HH-associated muscle loss. Methodology: Simulated HH exposure was performed in an animal decompression chamber. Gastric oral administration of CAR (50 mg·kg-1) and ALA (450 mg·kg-1) were given daily for 3 days and at the end of the treatment, hindlimb skeletal muscle tissue was excised for western blot and biochemical assays. Results: Cosupplementation of CAR and ALA alone was able to ameliorate the hypoxia-induced inflammation, oxidative stress (FOXO), ER stress (GRP-78), and atrophic signaling (MuRF-1) in the skeletal muscles. Creatinine phospho kinase activity and apoptosis were also decreased in CAR- and ALA-supplemented rats. However, CAR showed enhanced protection in HH-induced muscle loss as CAR supplementation was able to enhance protein concentration, body weight, and decreased the protein oxidation and ALA administration was not able to restore the same. Conclusions: Hence, the present comprehensive study supports the fact that CAR (50 mg·kg-1) is more beneficial as compared with ALA (450 mg·kg-1) in ameliorating the hypoxia-induced skeletal muscle loss.

中文翻译：

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L-肌肽和 β-丙氨酸改善低压缺氧引起的骨骼肌蛋白损失的比较生化研究。

Rathor、Richa、Sukanya Srivastava 和 Geetha Suryakumar。L-肌肽和 β-丙氨酸改善低压缺氧引起的骨骼肌蛋白损失的比较生化研究。High Alt Med Biol 00:000-000, 2023。背景：肌肽（CAR；β-丙氨酰-L-组氨酸）是一种生物活性二肽，以其独特的 pH 缓冲能力、金属螯合活性以及抗氧化和抗糖化特性而闻名。β-丙氨酸 (ALA) 是一种非必需氨基酸，用于增强表现和认知功能。低压缺氧（HH）引起的肌肉蛋白损失受到多方面信号通路的调节。本研究调查了 CAR 和 ALA 对 HH 相关肌肉损失的有益作用。方法：在动物减压室中进行模拟 HH 暴露。每天胃部口服CAR（50 mg·kg-1）和ALA（450 mg·kg-1），持续3天，治疗结束时，切除后肢骨骼肌组织进行蛋白质印迹和生化检测。结果：单独补充 CAR 和 ALA 能够改善骨骼肌中缺氧诱导的炎症、氧化应激 (FOXO)、内质网应激 (GRP-78) 和萎缩信号传导 (MuRF-1)。补充 CAR 和 ALA 的大鼠的肌酐磷酸激酶活性和细胞凋亡也有所降低。然而，CAR 对 HH 引起的肌肉损失表现出增强的保护作用，因为补充 CAR 能够提高蛋白质浓度、体重并减少蛋白质氧化，而 ALA 给药无法恢复相同的效果。结论：因此，本综合研究支持以下事实：与 ALA (450 mg·kg-1) 相比，CAR (50 mg·kg-1) 在改善缺氧引起的骨骼肌损失方面更有益。