Sensitivity to dioxin decreases as zebrafish mature.

ABSTRACT: The embryos of teleost fish are exquisitely sensitive to the toxic effects of exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, several lines of evidence suggest that adults are less sensitive to TCDD. To better understand and characterize this difference between early life stage and adults, we exposed zebrafish (Danio rerio) to graded TCDD concentrations at different ages. The LD(50) for embryos exposed at 1 day post-fertilization (dpf) was more than an order of magnitude lower than it was for juveniles exposed at 30 dpf. The latency between exposure and response also increased with age. Embryo toxicity was characterized by marked cardiovascular collapse and heart malformation, whereas juveniles exposed at 30 dpf had no detectable cardiovascular toxicity. In juveniles, the

SUBMITTER: Lanham KA 

PROVIDER: S-EPMC3355311 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature