title: Development of an embryotoxicity test for Enchytraeus crypticus--the effect of Cd.
abstract: The existing standard enchytraeid reproduction test (ERT) concerns the assessment of effects on survival and reproduction. In the present study we optimized and propose an embryotoxicity test using Enchytraeus crypticus. Cadmium (Cd) was used as a test substance. Endpoints evaluated were embryo development, number of embryonic structures, Calcium (Ca) channels quantification and hatching success with macroscopic monitoring, histological and immunohistochemistry analysis. Results showed that Cd is embryotoxic for this species, causing a decrease in the hatching success (EC50=3.1mg/kg), a delay or disruption in formation of embryonic structures depending on concentrations (<5mg Cd/kg or ⩾16mg Cd/kg). Results from immunohistochemistry suggest a competitive binding between Cd and Ca for Ca channels, resulting in changes in Ca homeostasis. The use of the E. crypticus embryotoxicity test with the combination of histological and immunohistological tools provided a good option towards mechanistic information enhancing the importance of these tests to evaluate the hazard of chemicals and possible use in risk assessment.
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal(1).
authors.forename: Micael F M
authors.initials: MF
authors.lastname: Gonçalves
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal(1). Electronic address: ritabicho@ua.pt.
authors.forename: Rita C
authors.initials: RC
authors.lastname: Bicho
authors.affiliation: Department of Pathology and Molecular Immunology, Biomedical Sciences Institute of Abel Salazar, University of Porto, 4050-313 Porto, Portugal.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rêma
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal(1).
authors.forename: Amadeu M V M
authors.initials: AM
authors.lastname: Soares
authors.affiliation: Department of Pathology and Molecular Immunology, Biomedical Sciences Institute of Abel Salazar, University of Porto, 4050-313 Porto, Portugal.
authors.forename: Augusto M R
authors.initials: AM
authors.lastname: Faustino
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal(1).
authors.forename: Mónica J B
authors.initials: MJ
authors.lastname: Amorim
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D047108:Embryonic Development / Q000187:drug effects*; D004784:Environmental Monitoring / Q000379:methods*; D008018:Life Cycle Stages; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development; D012098:Reproduction / Q000187:drug effects; D018570:Risk Assessment; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: Cadmium; Embryonic development; Embryotoxicity; Histology; Immunohistochemistry