Hajirezaee Saeed, Ajdari Ashkan, Azhang Bizhan
Department of Fisheries Sciences and Engineering, Faculty of Natural Resources, University of Jiroft, Jiroft, Kerman, Iran.
Offshore Fisheries Research Center, Iranian Fisheries Sciences Institute, Agricultural Research, Education & Extension Organization (AREEO), Chabahar, Iran.
Comp Biochem Physiol C Toxicol Pharmacol. 2021 Jun;244:109004. doi: 10.1016/j.cbpc.2021.109004. Epub 2021 Feb 17.
In this study, a metabolomics approach was applied to investigate the metabolic responses of grey mullet, Mugil cephalus to toxicity induced by heavy metal, Pb (NO3). In addition, the study was followed by assessing the peroxidation index and histology of liver as supplementary data. Pb (NO3) exposure affected the plasma metabolome, especially four group metabolites including amino acids, methylated metabolites, energetic metabolites and citric acid intermediates. Pb (NO3) in medium and high concentrations (15 and 25 μg/l) increased the levels of plasma amino acids compared to control (P < 0.01). In contrast, Pb (NO3) decreased the plasma levels of methylated metabolites (P < 0.01). The ketogenic metabolites and glycerol levels significantly elevated in fish exposed to 25 μg/l Pb (NO3) (P < 0.01). The plasma glucose levels increased in treatment, 5 μg/l Pb (NO3) and after a decline in treatment 15 μg/l Pb (NO3) elevated again in treatment 25 μg/l Pb (NO3) (P < 0.01).The plasma levels of lactate significantly increased in fish exposed to 5 and 15 μg/l Pb (NO3) and then declined to initial levels in treatment, 25 μg/l Pb (NO3) (P < 0.01). The plasma levels of TCA cycle intermediates significantly elevated in treatments 15 and 25 μg/l Pb (NO3) (P < 0.01). As a biomarker of oxidative stress, the plasma levels of malondialdehyde (MDA) showed significant increases in Pb (NO3) exposed fish (P < 0.01). During exposure period, wide ranges of liver tissue damages were also observed in Pb (NO3) exposed fish. In conclusion, exposure to Pb (NO3) affected the metabolome content of blood in grey mullet, mainly through inducing the biochemical pathways related to the metabolism of the amino acids, energetic metabolites and methylated metabolites. Our results may help to understand the effects of heavy metals on fish hematology from a molecular point of view.
在本研究中，采用代谢组学方法来研究鲻鱼（ Mugil cephalus ）对重金属硝酸铅（Pb(NO₃)）诱导毒性的代谢反应。此外，该研究还通过评估肝脏的过氧化指数和组织学作为补充数据。硝酸铅暴露影响了血浆代谢组，尤其是四类代谢物，包括氨基酸、甲基化代谢物、能量代谢物和柠檬酸中间体。与对照组相比，中高浓度（15和25μg/l）的硝酸铅使血浆氨基酸水平升高（P < 0.01）。相反，硝酸铅降低了甲基化代谢物的血浆水平（P < 0.01）。在暴露于25μg/l硝酸铅的鱼中，生酮代谢物和甘油水平显著升高（P < 0.01）。在5μg/l硝酸铅处理组中血浆葡萄糖水平升高，在15μg/l硝酸铅处理组中下降后，在25μg/l硝酸铅处理组中再次升高（P < 0.01）。暴露于5和15μg/l硝酸铅的鱼中血浆乳酸水平显著升高，然后在25μg/l硝酸铅处理组中降至初始水平（P < 0.01）。在15和25μg/l硝酸铅处理组中三羧酸循环中间体的血浆水平显著升高（P < 0.01）。作为氧化应激的生物标志物，暴露于硝酸铅的鱼中血浆丙二醛（MDA）水平显著升高（P < 0.01）。在暴露期间，在暴露于硝酸铅的鱼中也观察到广泛的肝脏组织损伤。总之，暴露于硝酸铅影响了鲻鱼血液的代谢组含量，主要是通过诱导与氨基酸、能量代谢物和甲基化代谢物代谢相关的生化途径。我们的结果可能有助于从分子角度理解重金属对鱼类血液学的影响。
