As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not onlyhistopathologically but also statistically by counting of the small, medium and large sized (grades 1 to 3) vessels per unit area. Angiogenic response is concluded as the most sensitive parameter for rating of high concentrations of perchlorate exposure
