Effects Of Three Polycyclic Aromatic Hydrocarbons: Benzo[a]pyrene, Pyrene And Phenanthrene On Development Of Early Life Stages Of Sebastiscus Marmoratus

Sebastiscus marmoratus embryos on neurula stage and larvae after haching exposed to waterborne benzo[a]pyrene(B(a)P),pyrene(Py) and phenanthrene(Ph) at concentrations of 10,100,1000 ng/L,respectively.The physiological and biochemical parameters were measured to assess the development toxicity of B(a) P (5 rings),Py(4 rings) and Ph(3 rings) to the embryos and larvae.The main results as follows:1.The mortality and malformations such as pericardial and yolk sac edema,spinal curvature mediated by these PAHs were elevated as the increasing of the exposure concentrations in a dose-dependent manner.Ph caused the highest rate of mortality while Py resulted in the highest rate of malformations.From the results,we found the alterations in mortality,malformations and reduction of craniofacial skeleton in treated embryos on neurula stage were more evidence than that in larvae after haching, which suggests that,embryos on neurula stage are more sensitive to PAHs than the larvae after haching.2.In this study,embryos and larvae treated by PAHs for 8 days shown a reduction in the size of the craniofacial skeleton in a dose-dependent manner.All the three PAHs caused the reduction of craniofacial skeletal elements,bent and shorten of Meckel's cartilage,while severity of the defects of ceratobranchial and trabecular correlated with the increasing of the concentration of Py and Ph.Py resulted in the most acute reduction of craniofacial skeleta.3.RARa expression in the embryos and the larvae exposed to B(a) P,Py,Ph for 8 days was assayed by western blotting and immunofluorescence technique using the polyantibody.The results showed that RARa expression were reduced in the PAHs -treated embryos and larvae in a dose-dependent manner.Py caused the most acute reduction of RARa expression.4.This study assayed the activity of Ca²⁺—ATPase and Na⁺,K⁺—ATPase in the embryos and larvae exposed to B(a) P,Py,Ph.The results showed that Ca²⁺—ATPase and Na⁺,K⁺—ATPase activity were reduced in the PAHs-treated embryos and larvae in a dose-dependent manner.Py caused the most acute reduction of Ca²⁺—ATPase and Na⁺,K⁺—ATPase activity.5.In tne three PAHs,Py caused the highest rate of malformations,the most acute reduction of craniofacial skeleta,the most acute reduction of RARa expression and the most acute reduction of Ca²⁺—ATPase and Na⁺,K⁺—ATPase activity which suggests that Py caused the most acute development toxicity among the three PAHs. This study evaluated and compared the toxicity of these three individual PAHs on the development of the embryos and larvae.The results showed that PAHs mediated development toxicity at low concentration.This result provide a evidence for the Environmental Standards Formulating.There would be a common modle of mechanisms by which these three PAHs mediated development toxicity.This conclusion provide new ideas for investigating the target and mechanism of PAHs mediated development toxicity.