Nitrite is a toxic substance found in rearing water that affects shrimp health. The hepatopancreas is an important digestive, immune, and metabolic organ in the shrimp. In this study, shrimps (Litopenaeus vannamei) were separately exposed to 1 and 5 mg/L nitrite stress for 48 h, and the toxicity of nitrite in the hepatopancreas was explored by integrating histology, physiological indicators, energy metabolism, and metabolomics. Nitrite stress induced morphological changes and stress responses in the hepatopancreas. Specifically, physiology-related indices, such as the relative gene expression levels of antioxidants (ROMO1, Nrf2, GPx), endoplasmic reticulum stress (Bip, IRE1 and XBP1), and immune genes (ALF, Pen-3, Lys) were decreased, whereas the gene expression of apoptosis (Casp-3), detoxification (CYP450), and glutamic oxaloacetic transaminase (GOT) activity were increased. The activities of osmotic adjustment-related enzymes (NKA, CMA, and ATPase) also decreased. Energy metabolism-related indices, such as pyruvate and hepatic glycogen contents, increased, whereas glucose, lactic acid, triglyceride, and ATP contents and ATPase activity decreased, and the relative gene expression levels of carbohydrate metabolism (PDH, HK, and LDH) and electron-transport chain genes (CytC, COI and CCO) decreased, and the expressions of lipid metabolism (AMPK, SREBP, and FAS), tricarboxylic acid cycle (MDH, CS, IDH and FH) genes were also disturbed. The metabolic pattern of the hepatopancreas was affected by nitrite stress. Glycine, serine, and threonine metabolism were highly affected, and more functional amino acids varied in the 5 mg/L nitrite stress group. These results reveal the toxic effects of nitrite stress on the stress response, physiology, energy metabolism, and metabolite homeostasis in the hepatopancreas of shrimp. Several potential metabolite biomarker candidates were identified for toxicological evaluation.

中文翻译：

---

综合生理、能量代谢和代谢组学反应表明南滨对虾肝胰腺对亚硝酸盐胁迫的应激反应


亚硝酸盐是一种在饲养水中发现的有毒物质，会影响虾的健康。肝胰腺是虾中重要的消化、免疫和代谢器官。本研究将虾 （Litopenaeus vannamei） 分别暴露于 1 mg/L 和 5 mg/L 亚硝酸盐胁迫下 48 h，通过整合组织学、生理指标、能量代谢和代谢组学，探讨亚硝酸盐在肝胰腺中的毒性。亚硝酸盐胁迫诱导肝胰腺的形态变化和胁迫反应。具体而言，抗氧化剂 （ROMO1 、 Nrf2 、 GPx） 、内质网应激 （Bip 、 IRE1 和 XBP1） 和免疫基因 （ALF、Pen-3 、 Lys） 的相对基因表达水平降低，而细胞凋亡 （Casp-3） 、解毒 （CYP450） 和谷氨酸草酰乙酸转氨酶 （GOT） 活性的基因表达增加。渗透调节相关酶 （NKA 、 CMA 和 ATP 酶） 的活性也降低。丙酮酸和肝糖原含量等能量代谢相关指标升高，葡萄糖、乳酸、甘油三酯和 ATP 含量和 ATP 酶活性降低，碳水化合物代谢（PDH、HK 和 LDH）和电子传递链基因（CytC、COI 和 CCO）的相对基因表达水平降低，脂质代谢（AMPK、SREBP 和 FAS）、三羧酸循环（MDH、 CS 、 IDH 和 FH） 基因也受到干扰。肝胰腺的代谢模式受亚硝酸盐应激的影响。甘氨酸、丝氨酸和苏氨酸代谢受到高度影响，5 mg/L 亚硝酸盐应激组的功能性氨基酸更多。 这些结果揭示了亚硝酸盐胁迫对虾肝胰腺应激反应、生理学、能量代谢和代谢物稳态的毒性作用。确定了几种潜在的代谢物候选物用于毒理学评估。