Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, ISA, Chott-Mariem, Sousse, Tunisia.
Arch Environ Contam Toxicol. 2012 Nov;63(4):534-43. doi: 10.1007/s00244-012-9790-3. Epub 2012 Aug 19.
The present research work was designed to study mussel's (Mytilus galloprovincialis) digestive gland biotransformation and detoxification responses to benzo[a]pyrene (B[a]P) exposure along with heat stress. Mussels were exposed to a sublethal dose of B[a]P [75 nM (19 μg/L/animal)] + temperature gradient (18, 20, 22, 24 and 26 °C) for 7 days. B[a]P hydroxylase (BPH) and glutathione-S-transferase (GST) activities were assessed in digestive gland tissues as phase I and phase II biotransformation parameters. Catalase (CAT) activity and malonedialdehyde (MDA) were measured as potential biomarkers of oxidative stress and lipid peroxidation. The cholinergic system was evaluated using acetylcholinesterase (AChE) activity. DNA damage was assessed using micronuclei (MN) test. BPH and GST activities showed a decreasing trend in B[a]P-exposed animals at 24 and 26 °C. CAT activity showed a bell-shaped response in B[a]P-exposed and in heat-stressed organisms at a maximum temperature of 22 °C. AChE activity was significantly inhibited in response to B[a]P being more pronounced at a temperature of 26 °C. MN in digestive gland cells suggest that B[a]P exposure induced significant DNA alteration with a maximum response in organisms coexposed to B[a]P and a temperature of 26 °C. Biomarker data are further discussed in relation B[a]P accumulation in mussels digestive gland. These data should be carefully considered in view of the biological effects of organic pollutants, particularly in organisms under the challenging effects of extreme temperature fluctuations.
本研究旨在研究贻贝（Mytilus galloprovincialis）消化腺在苯并[a]芘（B[a]P）暴露以及热应激下的生物转化和解毒反应。贻贝暴露于亚致死剂量的 B[a]P [75 nM（19 μg/L/动物）]+温度梯度（18、20、22、24 和 26°C）7 天。作为 I 相和 II 相生物转化参数，评估了消化腺组织中的苯并[a]芘羟化酶（BPH）和谷胱甘肽-S-转移酶（GST）活性。过氧化氢酶（CAT）活性和丙二醛（MDA）作为氧化应激和脂质过氧化的潜在生物标志物进行了测量。通过乙酰胆碱酯酶（AChE）活性评估了胆碱能系统。使用微核（MN）试验评估了 DNA 损伤。在 24 和 26°C 下，B[a]P 暴露动物的 BPH 和 GST 活性呈下降趋势。在 22°C 的最高温度下，B[a]P 暴露和热应激生物体内的 CAT 活性呈钟形反应。AChE 活性对 B[a]P 的抑制作用显著，在 26°C 的温度下更为明显。消化腺细胞中的 MN 表明，B[a]P 暴露诱导了显著的 DNA 改变，在同时暴露于 B[a]P 和 26°C 温度的生物体内反应最大。生物标志物数据与贻贝消化腺中 B[a]P 积累有关进一步讨论。鉴于有机污染物的生物学效应，特别是在生物体受到极端温度波动的挑战性影响下，应仔细考虑这些数据。
