This study aimed to explore the mechanism underlying arginine-promoted myogenesis of myoblasts. C2C12 cells were cultured with a medium containing 0.1, 0.4, 0.8, or 1.2 mmol/L arginine, respectively. Cell proliferation, viability, differentiation indexes, cytoplasmic Ca²⁺ concentration, and relative mRNA expression levels of myogenic regulatory factors (MRF) and key Ca²⁺ channels were measured in the absence or presence of 2 chemical inhibitors, dantrolene (DAN, 10 μmol/L) and nisoldipine (NIS, 10 μmol/L), respectively. Results demonstrated that arginine promoted myogenic differentiation and myotube formation. Compared with the control (0.4 mmol/L arginine), 1.2 mmol/L arginine upregulated the relative mRNA expression levels of myogenin (MyoG) and Myomaker at d 2 during myogenic induction (P < 0.05). Cytoplasmic Ca²⁺ concentrations were significantly elevated by arginine supplementation at d 2 and 4 (P < 0.05). Relative mRNA expression levels of Ca²⁺ channels including the type 1 ryanodine receptor (RyR1) and voltage-gated Ca²⁺ channel (Cav1.1) were upregulated by 1.2 mmol/L arginine during 2-d myogenic induction (P < 0.01). However, arginine-promoted myogenic potential of myoblasts was remarkably compromised by DAN and NIS, respectively (P < 0.05). These findings evidenced that the supplementation of arginine promoted myogenic differentiation and myotube formation through increasing cytoplasmic Ca²⁺ concentration from both extracellular and sarcoplasmic reticulum Ca²⁺.

本研究旨在探讨精氨酸促进成肌细胞成肌的机制。C2C12 细胞分别用含有 0.1、0.4、0.8 或 1.2 mmol/L 精氨酸的培养基培养。细胞增殖，生存力，分化指标，细胞质的Ca ²⁺浓度，生肌调节因子（MRF）和密钥的Ca相对mRNA表达水平²⁺通道在不存在或2化学抑制剂，丹曲林存在（DAN，10微摩尔，测定/L) 和尼索地平 (NIS, 10 μmol/L)。结果表明精氨酸促进肌源性分化和肌管形成。与对照 (0.4 mmol/L 精氨酸) 相比，1.2 mmol/L 精氨酸上调了肌细胞生成素 ( MyoG)的相对 mRNA 表达水平和肌原性诱导期间第 2 天的 Myomaker ( P  < 0.05)。在第 2 天和第 4 天补充精氨酸可显着提高细胞质 Ca ²⁺浓度（P  < 0.05）。Ca ²⁺通道的相对mRNA 表达水平，包括1 型兰尼碱受体（RyR1）和电压门控Ca ²⁺通道（Cav1.1）在2-d 肌源性诱导期间被1.2 mmol/L 精氨酸上调（P  < 0.01） . 然而，DAN 和 NIS 分别显着损害了成肌细胞的精氨酸促进生肌潜力（P < 0.05)。这些发现证明，精氨酸的补充通过增加来自细胞外和肌质网 Ca ^{2+ 的}细胞质 Ca ²⁺浓度来促进生肌分化和肌管形成。