It is well known that preslaughter (antemortem) stress such as rough handling, transportation, a negative environment, physical discomfort, lack of consistent routine, and bad feed quality has a big impact on meat quality. The antemortem-induced poor meat quality is characterized by low pH, a pale and exudative appearance, and a soft texture. Previous studies indicate that antemortem stress plays a key role in regulating protein acetylation and glycolysis in postmortem (PM) muscle. However, the underlying molecular and biochemical mechanism is not clearly understood yet. In this study, we investigated the relationship between antemortem and protein acetylation and glycolysis using murine longissimus dorsi muscle isolated from ICR mice and murine muscle cell line C₂C₁₂ treated with epinephrine hydrochloride. Because adrenaline secretion increases in stressed animals, epinephrine hydrochloride was intraperitoneally injected epinephrine into mice to simulate pre-slaughter stress in this study to facilitate experimental operations and save experimental costs. Our findings demonstrated that protein acetylation in pyruvate kinase M1 (PKM1) form is significantly reduced by antemortem, and the reduced acetylation subsequently leads to an increase in PKM1 enzymatic activity which causes increased glycolysis in PM muscle. By using molecular approaches, we identified lysine 141 in PKM1 as a critical residue for acetylation. Our results in this study provide useful insight for controlling or improving meat quality in the future.

众所周知，屠宰前（宰前）应激，如粗暴的处理、运输、负面环境、身体不适、缺乏一致的常规以及不良的饲料质量，对肉质有很大影响。宰前引起的肉质不良的特点是pH值低、外观苍白、有渗出物、质地柔软。先前的研究表明，死前应激在调节死后（PM）肌肉中的蛋白质乙酰化和糖酵解中起着关键作用。然而，潜在的分子和生化机制尚不清楚。在这项研究中，我们使用从ICR小鼠中分离的鼠背最长肌和用盐酸肾上腺素处理的鼠肌细胞系C ₂ C ₁₂来研究生前与蛋白质乙酰化和糖酵解之间的关系。由于应激动物肾上腺素分泌增多，本研究通过给小鼠腹腔注射盐酸肾上腺素模拟屠宰前应激，以方便实验操作，节省实验成本。我们的研究结果表明，丙酮酸激酶 M1 (PKM1) 形式的蛋白质乙酰化在生前显着减少，乙酰化减少随后导致 PKM1 酶活性增加，从而导致 PM 肌肉糖酵解增加。通过使用分子方法，我们确定 PKM1 中的赖氨酸 141 是乙酰化的关键残基。我们的研究结果为未来控制或改善肉类质量提供了有用的见解。