pH和菲协同效应对中华绒螯蟹幼蟹的毒性效应

Synergistic effects of pH and phenanthrene on toxicity of juvenile Chinese mitten crab(Eriocheir sinensis)

为探究酸化以及环境污染物菲(Phenanthrene,PHE)协同效应对中华绒螯蟹(Eriocheir sinensis)的影响,开展了不同pH(5.5、6.5、7.8)和PHE质量浓度(0、50μg·L^(−1))对中华绒螯蟹[(15.0±2.3)g]的联合暴露实验(为期14 d)。结果发现:1)中华绒螯蟹在pH 5.5×PHE 50的协同处理下,肝胰腺和鳃组织出现严重病理损伤,肝胰腺小管形状改变,肝管细胞萎缩出现大量空泡,鳃轴肿大,鳃丝角质层表皮破损,局部基膜破裂;而pH 6.5×PHE 50对中华绒螯蟹肝胰腺和鳃组织的损伤并不显著。2)PHE处理引起中华绒螯蟹幼蟹肝胰腺糖原(Gly)以及低密度脂蛋白胆固醇(LDL-C)浓度显著降低,表明PHE会导致中华绒螯蟹能量代谢水平下降;相较于对照组,pH 5.5×PHE 50对甘油三酯(TG)、Gly、高密度脂蛋白胆固醇(HDL-C)和LDL-C浓度均有抑制效果,而pH 6.5×PHE 50使得中华绒螯蟹TG浓度较对照组显著升高。3)实时荧光定量PCR结果表明,多环芳烃受体(ahr)、芳香烃受体核转位因子(arnt)和细胞色素p4501A1(cyp1a1)基因的表达量均随pH的降低而升高,并在pH 5.5时达到最高。以上结果表明,酸化和PHE的联合作用改变了中华绒螯蟹的能量代谢,其中pH 5.5时显著加剧了PHE对其肝胰腺组织结构的毒性作用以及对能量代谢的影响。

In order to explore the synergistic effects of acidification and environmental pollutant phenanthrene(PHE)on Chi-nese mitten crabs(Eriocheir sinensis),we carried out a 14-day joint exposure experiment of E.sinensis[(15.0±2.3)g]to different pH(5.5,6.5,7.8)and PHE(0,50μg·L^(−1)).The results show that:1)Under the synergistic treatment of pH 5.5×PHE 50 on E.sinensis,the hepatopancreas and gill tissues were severely damaged;the shape of the hepatopancreatic tubules changed;a large number of vacuoles appeared in the atrophy of the hepatic duct cells.The gill axis was enlarged;the cuticle of the gill filament was damaged;the local basement membrane was ruptured.However,pH 6.5×PHE 50 did not significantly damage the hepatopancreas and gill tissues of E.sinensis.2)PHE treatment significantly reduced the contents of Gly and LDL-C in hepatopancreas of juvenile E.sinensis,indicating that PHE could decrease the energy metabolism level of E.sinensis.Compared with the control group,pH 5.5×PHE 50 inhibited the contents of TG,Gly,HDL-C and LDL-C,while pH 6.5×PHE 50 significantly increased TG content.3)Real-time fluorescent quantitative PCR experiment shows that AHR,ARNT and CYP1A1 increased significantly with the decrease of pH,and reached the highest values at pH 5.5.The results reveal that the combining effect of acidification and PHE changes the energy metabolism of E.sinensis,and pH 5.5 significantly aggravates the toxic effect of PHE on the hepatopancreas tissue structure of E.sinensis,as well as its energy metabolism.