Zhang Xiangli, Du Pengfei, Wang Ziyang, Zhu Yao, Si Xuemeng, Chen Wen, Huang Yanqun
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, Henan 450046, China.
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, Henan 450046, China.
Poult Sci. 2025 Jan;104(1):104619. doi: 10.1016/j.psj.2024.104619. Epub 2024 Dec 2.
Birds' glycolipid metabolism has garnered considerable attention due to their fasting blood glucose levels being nearly twice those of mammals. While skeletal muscle is the primary insulin-sensitive tissue in mammals, the effects of insulin on chicken skeletal muscle remain unclear. In this study, the insulin-responsive metabolites were identified in broiler's pectoralis muscle (after 16 h of fasting) using widely targeted metabolomics. Glycolipid concentrations were measured using kits, and the expression of key genes involved in glucose metabolism was assessed via quantitative real-time PCR (qRT-PCR). The insulin tolerance test, performed by injecting 5 IU/kg body weight of insulin, demonstrated a rapid drop in blood glucose levels from 0 to 15 min, with a consistent reduction observed at 120 min (P < 0.01). Insulin did not alter glucose and glycogen content in chicken pectoralis; however, low-density lipoprotein (LDL, P < 0.05) levels were upregulated in the early phase (15 min). With an extended insulin duration (120 min), pectoralis glucose content increased (P < 0.05), accompanied by a reduction in TG levels (P < 0.05). Metabolomic analysis revealed that insulin promotes the downregulation of 63 out of 71 metabolites at 15 min and the upregulation of 101 out of 134 metabolites at 120 min, mainly associated with lysine degradation and thyroid hormone signaling pathways, respectively. 7 metabolites were dynamically modulated in the same manner over time (2 up-up and 5 down-down). Early insulin inhibited glycolysis, evidenced by the reduction in phosphoenolpyruvate levels and hexokinase 2 (HK2) expression; however, insulin promoted glucose uptake through the activation of glucose transporter 4 (GLUT4) and enhanced glycolysis, accompanied by elevated fatty acid metabolism at the later phase. In conclusion, insulin dynamically regulates the metabolomics of the pectoralis muscle over time. Initially, chicken muscle tissues downregulate metabolic activities to accommodate the new signaling state, followed by significant upregulation to meet heightened metabolic demands. Extended insulin monitoring promotes glucose uptake and glycolysis, alongside enhanced fatty acid metabolism. This research provides insights into the potential mechanisms of insulin action in chicken muscles.
由于鸟类的空腹血糖水平几乎是哺乳动物的两倍,其糖脂代谢受到了广泛关注。虽然骨骼肌是哺乳动物主要的胰岛素敏感组织,但胰岛素对鸡骨骼肌的影响尚不清楚。在本研究中,利用广泛靶向代谢组学技术,在禁食16小时后的肉鸡胸肌中鉴定出胰岛素反应性代谢物。使用试剂盒测量糖脂浓度,并通过定量实时PCR(qRT-PCR)评估参与葡萄糖代谢的关键基因的表达。通过注射5 IU/kg体重的胰岛素进行胰岛素耐量试验,结果显示血糖水平在0至15分钟内迅速下降,在120分钟时持续降低(P < 0.01)。胰岛素并未改变鸡胸肌中的葡萄糖和糖原含量;然而,低密度脂蛋白(LDL,P < 0.05)水平在早期(15分钟)上调。随着胰岛素作用时间延长至120分钟,胸肌中的葡萄糖含量增加(P < 0.05),同时甘油三酯(TG)水平降低(P < 0.05)。代谢组学分析表明,胰岛素在15分钟时促使71种代谢物中的63种下调,在120分钟时促使134种代谢物中的101种上调,分别主要与赖氨酸降解和甲状腺激素信号通路相关。有7种代谢物随时间以相同方式动态调节(2种先上调后上调,5种先下调后下调)。早期胰岛素抑制糖酵解,磷酸烯醇丙酮酸水平和己糖激酶2(HK2)表达降低证明了这一点;然而,胰岛素通过激活葡萄糖转运蛋白4(GLUT4)促进葡萄糖摄取并增强糖酵解,后期伴随着脂肪酸代谢增强。总之,胰岛素随时间动态调节胸肌的代谢组学。最初,鸡肌肉组织下调代谢活动以适应新的信号状态,随后显著上调以满足增加的代谢需求。延长胰岛素作用时间可促进葡萄糖摄取和糖酵解,同时增强脂肪酸代谢。本研究为胰岛素在鸡肌肉中的作用潜在机制提供了见解。