Faculty of Sciences of Tunis, Biology Department, Research, Laboratory of Ecology, Biology and Physiology of Aquatic Organisms, University of Tunis El Manar, Tunis, Tunisia.
Anatomy and Cytology Service, Mohamed Taher Maamouri Hospital, Nabeul, Tunisia.
Drug Chem Toxicol. 2022 Jan;45(1):311-323. doi: 10.1080/01480545.2019.1693590. Epub 2019 Nov 22.
The aim of this study is to elucidate the toxicity induced by PbCl, administered in graded doses (1; 2.5; 5 mg/L), in the redox state, in the fatty acid composition and in the histological structure of digestive glands. Our findings showed a progressive accumulation of Pb in the digestive glands in all treated groups. After 5 days of treatment with PbCl, an increase in HO, MDA, PCO, GSH, NPSH and MT levels was observed in the digestive glands of treated groups. Moreover, activities of antioxidant enzymes, such as GPx and CAT, increased while SOD activity decreased in all treated groups, indicating a failure of the antioxidant defense system. Furthermore, the cholinergic function was evaluated by assessing the acetylcholinesterase activity, which was inhibited in all the treated digestive glands compared to the control group. In our experiment, the levels of -3 (Omega-3) and -6 (Omega-6) polyunsaturated fatty acids were greatly altered in the groups treated with 5 mg/L of PbCl ( < 0.001). Indeed, DHA and EPA decreased significantly in the digestive glands treated with 2.5 and 5 mg/L of PbCl, respectively. On the other hand, under exposure to the medium and high doses (2.5 and 5 mg/L), arachidonic acid (ARA) and linoleic acid (LA) significantly increased ( < 0.001). These changes in PUFA were confirmed by significant modifications in the polyene and peroxidation indices. The histological findings confirmed the biochemical results.HighlightsIntegrated parameters were used to explore the toxic effect of PbCl graded doses digestive gland.Metals accumulation in digestive glands of was greatly dependent to dose of PbCl.Metabolic and macromolecules damaging of clams digestive glands were more sensitive at higher PbCl doses.Fatty acids composition especially polyunsaturated fatty acids (PUFA) and essentials fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in clams digestive glands were intensively altered at higher PbCl doses.Inflammation responses revealed in studied tissue.
本研究旨在阐明 PbCl 以递增剂量（1、2.5、5mg/L）给药时对消化腺氧化还原状态、脂肪酸组成和组织结构造成的毒性。我们的研究结果显示，所有实验组的消化腺中 Pb 均逐渐累积。PbCl 处理 5 天后，实验组消化腺中的 HO、MDA、PCO、GSH、NPSH 和 MT 水平均升高。此外，所有实验组的抗氧化酶（如 GPx 和 CAT）活性升高，SOD 活性降低，表明抗氧化防御系统失效。此外，通过评估乙酰胆碱酯酶活性来评估胆碱能功能，结果显示所有实验组的消化腺均受到抑制。在我们的实验中，处理组的 -3（欧米伽 3）和 -6（欧米伽 6）多不饱和脂肪酸水平发生了巨大变化（ < 0.001）。事实上，分别用 2.5 和 5mg/L 的 PbCl 处理后，消化腺中的 DHA 和 EPA 显著减少。另一方面，在暴露于中高剂量（2.5 和 5mg/L）时，花生四烯酸（ARA）和亚油酸（LA）显著增加（ < 0.001）。多不饱和脂肪酸的这些变化得到了多烯和过氧化指数的显著改变的证实。组织学发现证实了生化结果。综合参数用于探索 PbCl 递增剂量对消化腺的毒性作用。消化腺中金属的积累对 PbCl 剂量的依赖性很大。在更高剂量的 PbCl 作用下，贻贝消化腺的代谢和大分子损伤更为敏感。贻贝消化腺中的脂肪酸组成，特别是多不饱和脂肪酸（PUFA）和必需脂肪酸，如二十二碳六烯酸（DHA）和二十碳五烯酸（EPA），在更高剂量的 PbCl 作用下受到强烈影响。在研究组织中发现炎症反应。
