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Study on Combination Toxicity Effects of Cadmium and Benzo [α] Pyrene on Clam Ruditapes Philippinarum

Author: WangLin
Tutor: PanLuQing
School: Ocean University of China
Course: Aquaculture
Keywords: Cd B [a] P Combined pollution Ruditapes philippinarum Accumulation Detoxification indicators Gene Expression
CLC: X174
Type: Master's thesis
Year: 2010
Downloads: 148
Quote: 1
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Abstract

In recent years, China's pollution of the marine environment is increasing, serious security threat to the survival of marine life and the marine environment. Heavy metal pollution has lasted for a long time, bio non-degradable and relative stability, and polycyclic aromatic hydrocarbons (Polycyclic aromatic hydrocarbon, PAHs) as components of petroleum hydrocarbons, carcinogenic, teratogenic and mutagenic effects, including benzo [α] pyrene (Benzo [α] pyrene, B [α] P) is the most carcinogenic of PAHs. These two pollutants on marine organisms not only with a single toxic, and often interact to produce a composite pollution. But little research on the dangers of heavy metal-PAHs composite pollutants on marine organisms. The papers choose buried habitat type lifestyle Philippine clams (Ruditapes philippinarum) as the object of study, research Ruditapes philippinarum of Cd2-B [α] P composite pollution stress, acute toxicity, accumulation law detoxification metabolic markers and gene expression changes explore the mechanism of toxicity of the heavy metal-PAHs composite contamination of bivalve molluscs, got the following results: 1 of Cd2-B [α] P single and combined pollution on the of Ruditapes philippinarum acute toxic effects of the study this experimental study Cd2 -B [α] P composite pollution Ruditapes philippinarum acute toxicity. The results show that, Cd2 Ruditapes philippinarum 24,48,72,96 h LC50 were 119.23,50.41,24.12,14.68 mg / L, B [a] P Ruditapes philippinarum single exposure LC50 gt; 10 mg / L of Cd2 -B [alpha] P joint acute toxicity 24h Ruditapes philippinarum performance showed antagonism ,48-96h synergies. Shows, Ruditapes philippinarum Cd2-B [α] P composite stress apparent acute toxic effects, and the combined pollution pollutants composition, concentration and duration of action, and other factors. 2 of Cd2-B [α] P single and combined pollution Ruditapes philippinarum absorption study of the cumulative effects of this experiment research of Cd2 B [α] P single and Cd2-B [α] P composite pollution Ruditapes philippinarum gill digestive gland, adductor muscle and the soft part of the Cd2 and B [alpha] P concentration variation. The results showed that of Cd2 single exposure and Cd2-B [α] P composite exposure, Ruditapes philippinarum gill, digestive caeca software Cd2 concentration was significantly higher (P lt; 0.05), and the combined pollution group Cd2 was significantly higher than that of a single pollution group (P lt; 0.05), and the control group and the B [α] P single pollution Cd2 content no significant change (P gt; 0.05). B [α] P single and Cd2-B [α] P composite exposure, each exposure group Ruditapes philippinarum gill, digestive gland, the soft part of the B [α] P concentrations were significantly higher (P lt; 0.05), and The combined pollution group B [alpha] P content was significantly higher than that of the single pollution group (P lt; 0.05), the control group,, with Cd2 single pollution group B [α] P showed no significant change (P gt; 0.05). The digestive caeca pollutant content was significantly higher than the gills during the experiment, no significant changes (P gt adductor muscle; 0.05). It showed strong enrichment Ruditapes philippinarum the Cd2 and B in the environment [α] P, and the combined pollution strengthen this enrichment capacity. 3 of Cd2-[α] P single and combined pollution impact on of Ruditapes philippinarum organization detoxification metabolic indicators of this experimental study Cd2-B [α] P compound pollution of Ruditapes philippinarum gill, digestive gland detoxification metabolic indicators of vitality . The results show that of Cd2 single pollution group Cd2-B [α] P the the combined pollution metallothionein (metallothionein, MT) content showed a peak change in the 12d, 1d, 3d reach maximum stabilized after 12 days, significant higher than the control level (P lt; 0.05). And the same Cd2 exposure concentration, combined pollution group MT content was significantly lower than the single-exposure group (P lt; 0.05). B [α] P single pollution group with Cd2-B [α] P the combined pollution aromatics hydroxylase (aryl hydrocarbon hydroxylase, AHH) activity in 6d was first increased and then decreased change, respectively, 1d, 3d reached the maximum The, 6d stabilized, significantly higher than the control level (P lt; 0.05). And at the same B [α] P exposure concentration, combined pollution group AHH activity was significantly lower than the single-exposure group (P lt; 0.05). Single exposure group organization glutathione (glutathione, GSH) levels showed a peak change in the 12d, 1d, 3d reach maximum stable after 12 days, the performance of the recovery to the level of the control group (P gt; 0.05) or be induced (P lt; 0.05); the composite pollution treatment group GSH content in addition to Cd B [α] P (15μg / L 0.01μg / L) treatment group showed a peak change in 3d, the other treatment groups showed a gradual downward trend are stable after 12d was significantly inhibited (P lt; 0.05). Each exposure treated tissue glutathione S-transferase enzymes (glutathione S-transferase, GST) and superoxide dismutase (superoxide dismutase, SOD) activity showed a peak change within 12d, respectively 1d, 3d reached the maximum, 12d after each treatment group GST, SOD vitality stabilized GST vitality and the control group had no significant difference (P gt; 0.05), SOD activity was significantly higher than the control level (P lt; 0.05), and the composite pollution on GSH content GST and SOD inhibition induced significantly greater than a single contamination (P lt; 0.05). Various indicators of the control group did not change significantly (P gt; 0.05). Thus, the Philippines clams in Cd2-B [α] P composite stress under detoxification indicators vitality changes showed significant time, the dose effect of to produce composite pollution toxic effects. 4 of Cd2-B [α] P single and combined pollution impact of of Ruditapes philippinarum organization detoxification gene expression in this experimental study of Cd2-B [α] P the composite pollution of Ruditapes philippinarum gill, digestive caeca GST-pi and Cu, Zn-SOD gene expression. The results show that each exposure group is GST-pi gene expression showed a peak change in 6d, reaches its maximum at 1d or 3d, then gradually declined 6d restored to the control group level (P gt; 0.05), while in 6d within The degree of composite pollution GST-pi mRNA expression induced significantly greater than a single contamination (P lt; 0.05). Each exposure group Cu, Zn-SOD gene expression showed a peak change in 6d reached the maximum ,6-21d, respectively, at 1d or 3d stable, but still significantly higher level (P lt; 0.05). Induction of combined pollution group was significantly greater than a single contamination group (P lt; 0.05). It showed that GST-pi and Cu, Zn-SOD gene expression amount and enzyme activity were basically consistent Cd2 and B [α] P composite pollution stress Ruditapes philippinarum regulation of GST and SOD function transcription level, but also shows the importance of biotransformation enzymes and antioxidant enzymes in the detoxification process and the close relationship.

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