Thyrring Jakob, Juhl Bodil Klein, Holmstrup Martin, Blicher Martin E, Sejr Mikael K
Department of Bioscience, Arctic Research Centre, Aarhus University, C. F. Møllers Allé 8, Building 1110, 8000, Aarhus C, Denmark.
Section of Soil Fauna Ecology and Ecotoxicology, Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark.
Ecotoxicology. 2015 Nov;24(9):2036-42. doi: 10.1007/s10646-015-1539-0. Epub 2015 Oct 6.
In their natural habitats, organisms are exposed to multiple stressors. Heavy metal contamination stresses the cell membrane due to increased peroxidation of lipids. Likewise, sub-zero air temperatures potentially reduce membrane functionality in ectothermal animals. We tested if acute lead (Pb) exposure for 7 days would influence survival in intertidal blue mussels (Mytilus edulis) after exposure to realistic sub-zero air temperatures. A full factorial experiment with five tissue Pb concentrations between 0 and 3500 μg Pb/g and six sub-zero temperatures from 0 to -17 °C were used to test the hypothesis that sub-lethal effects of Pb may increase the lethality caused by freezing in blue mussels exposed to temperatures simulating Greenland winter conditions. We found a significant effect of temperature on mortality. However, the short-term exposure to Pb did not result in any effects of Pb, nor did we find interactions between Pb and temperature. We analysed the relative abundance of major phospholipid fatty acids (PLFAs) in the gill tissue, but we found no significant effect of Pb tissue concentration on PLFA composition. Results suggest that Pb accumulation has limited effects on freeze tolerance and does not induce membrane damage in terms of persistent lipid peroxidation.
在自然栖息地中，生物体面临多种应激源。重金属污染会因脂质过氧化增加而使细胞膜受到应激。同样，零下气温可能会降低变温动物的膜功能。我们测试了潮间带蓝贻贝（紫贻贝）在暴露于实际零下气温之前，急性铅（Pb）暴露7天是否会影响其存活。采用了一个全因子实验，其中有五个介于0至3500μg Pb/g之间的组织铅浓度以及六个介于0至 -17°C之间的零下温度，以检验铅的亚致死效应可能会增加暴露于模拟格陵兰冬季条件温度下的蓝贻贝因冷冻导致的致死率这一假设。我们发现温度对死亡率有显著影响。然而，短期铅暴露并未产生任何铅效应，我们也未发现铅与温度之间的相互作用。我们分析了鳃组织中主要磷脂脂肪酸（PLFA）的相对丰度，但发现铅组织浓度对PLFA组成没有显著影响。结果表明，铅积累对耐寒性的影响有限，并且就持续性脂质过氧化而言不会诱导膜损伤。
