PW09 Exposure and Effect Endpoints
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW155) Developmental Effects of Methylene Chloride on Medaka Embryos.
Yenuganti, J1, Palit, S1, Thiyagarajah, A1, Hartley, W1, Abdelghani, A1, 1 Tulane University Health Sciences Center, New Orleans, LA, USA
ABSTRACT- Methylene chloride (MCL) is one of the common solvents found in the environment. The purpose of this study was to determine the effects of MCL on the developing medaka embryos. We selected five concentrations (125, 250, 375, 500 and 625 mg/L) of MCL and additional two environmentally relevant concentrations (0.1 and 0.01 mg/L) for this study. The stock solution of MCL was prepared in embryo rearing solution (ERS) and an appropriate amount of stock solution was added to the ERS to get the required concentrations. The control group received ERS only. Embryos at early high blastula stage (N=60 per concentration) were exposed to MCL individually for 10 days. The test solutions were renewed daily. Each embryo was evaluated for mortality and abnormalities daily and the lesions were followed through 10days. The study is still in progress. The developmental anomalies observed in our preliminary evaluation were slow development of some embryo, and cardiac (lack of chambers formation) and nervous system (brain and eye anomalies) malformations. The preliminary results suggest that MCL may be a developmental toxin. Funded in part by Department of Energy project number DE-FC26-00NT40843
Key words: Methylene chloride, Medaka, developmental toxicity, embryology