(±)-Carnitine chloride (Monocamin) is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine.

L-Carnitine chloride的主要作用是通过内线粒体膜运送长链脂肪酸。在肉碱棕榈酰转移酶（CPT）-I激活后，L-Carnitine chloride和酰基辅酶A变为酰基-肉碱，该运输的酰基-肉碱在线粒体基质中由CPT-II转变为酰基辅酶A。L-Carnitine chloride处理增加了棕榈酰辅酶A诱导的线粒体呼吸，并在ADP存在下被加速。这种加速由L-Carnitine chloride处理以浓度依赖的方式诱导，并在5 mM L-Carnitine chloride时达到饱和[1]。L-Carnitine chloride预处理增强了Water2处理的HL7702细胞中Nrf2核内转位、DNA结合活性和血红素氧合酶-1（HO-1）表达。通过Akt介导的Nrf2信号通路激活，L-Carnitine chloride保护HL7702细胞免受Water2诱导的细胞损伤[2]。

(±)-Carnitine chloride被发现能够下调泛素-蛋白酶体途径并增加动物模型中的IGF-1浓度。连续给予(±)-Carnitine chloride治疗2周的悬吊实验能够缓解腓肠肌重量和纤维尺寸的减少。此外，(±)-Carnitine chloride抑制atrogin-1 mRNA表达，该因子被认为在肌肉萎缩中发挥关键作用[3]。与(±)-Carnitine chloride的同时治疗减轻了与血浆TGF-β1水平降低相关的肾脏纤维化以及L-NAME组中报告的氧化和炎症状态，同时增加了PPAR-γ的表达[4]。

Mitochondria (0.6 mg protein/mL) are incubated in 2.5 mM Hepes (pH7.4) containing 225 mM mannitol, 75 mM sucrose and 100 μM ethylene glycol tetraacetic acid (EGTA) with or without 5 mM L-carnitine at 25°C. To measure oxygen uptake, 10 min after inorganic phosphate (Pi) 4 mM are added, the mitochondria are treated with palmitoyl-CoA (50 μM) and then ADP is added (200 μM). Oligomycin (5 μM) and rotenone (10 μM) are added 3-4 min after the ADP treatment. HPG (0-10 mM), which can specifically inhibit carnitine palmitoyl transferase (CPT)-I activity in the mitochondria, is added in the Hepes medium before incubation of the mitochondria[1].