title: Biomarker responses of earthworms (Eisenia fetida) exposured to phenanthrene and pyrene both singly and combined in microcosms.
abstract: Microcosm studies were undertaken to relate biomarker responses to the toxicities in soil ecosystems contaminated by phenanthrene (Phe) and pyrene (Pyr), both singly and combined. Growth inhibition, enzyme activity, MDA content, sperm count, neutral-red retention time (NRRT) and annetocin and TCTP gene transcriptions were determined in earthworm Eisenia fetida exposed to Phe and Pyr, both singly and combined pollution in microcosm. Exposure to 0.5 and 2.5 mg kg(-1) Phe or 50 and 100 mg kg(-1) Pyr alone significantly decreased E. fetida growth, NRRT and sperm count. Two-way ANOVA analysis shows that the combination of these two compounds decreased growth, SOD activities, NRRT and sperm count synergistically, but increased the CAT activities and MDA content. The highest suppression rate of growth was 48.12%, the lowest levels of SOD activities and NRRT were 51.66% and 45.57% of the control, respectively. The highest increase in CAT activities and MDA content were 120.05% and 121.03% greater than that of the control when exposed to 0.5 (Phe)+100 (Pyr) mg kg(-1) soils. A clear dose-related response with exposure concentration was established for the NRRT. Real-time PCR shows that Phe and Pyr increased the expression levels of annetocin and TCTP gene synergistically. These results demonstrate that earthworms were under physiological stress at field dose of 0.5 (Phe)+100 (Pyr) mg kg(-1) soils. Phe and Pyr synergistically decreased sperm count and NRRT, but antagonistically caused changes in antioxidant enzyme activities to disrupt the detoxification functions and inhibit earthworm growth.
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China.
authors.forename: Shijin
authors.initials: S
authors.lastname: Wu
authors.forename: Huaxing
authors.initials: H
authors.lastname: Zhang
authors.forename: Shiliang
authors.initials: S
authors.lastname: Zhao
authors.forename: Junliang
authors.initials: J
authors.lastname: Wang
authors.forename: Huilong
authors.initials: H
authors.lastname: Li
authors.forename: Jianmeng
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D007447:Invertebrate Hormones / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D009499:Neutral Red / Q000378:metabolism; D009835:Oligochaeta / Q000378:metabolism; D010456:Peptides, Cyclic / Q000378:metabolism; D010616:Phenanthrenes / Q000633:toxicity*; D011721:Pyrenes / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D015415:Biomarkers; D007447:Invertebrate Hormones; D010456:Peptides, Cyclic; D010616:Phenanthrenes; D011721:Pyrenes; D012989:Soil Pollutants; C085335:annetocin; D009499:Neutral Red; C031181:phenanthrene; D008315:Malondialdehyde; C030984:pyrene; D013482:Superoxide Dismutase