한국서해안에서 채취한 바지락의 EROD 활동도연구

Abstract

EROD (7-ethoxyresorufin-0-deethylase) activities in the digestive gland of Manila clams (Ruditapes philippinarum) were assayed in an attempt to select an early warning distresssignal of marine environmental degradation in the intertidal zone. The experiment showed a dose-response relationship for EROD induction in Mamila clams over wide concentration ranges of injected beta-naphthoflavone. The increase of EROD activity was highest in the digestive gland among difffrent organs of Manila clams amd showed a maximum in 45~50mm shell length animals. EROD activity and P45O level in the digestive gland of Manila clams by exposure concentrations of Benzo(a)pyrene (BaP), 2,2',4,4',5,5'-Hexachlorobiphenyl (CB-153) and 2,2',3,4,4',5,5'- Heptachlorobiphenyl (CB-180) were investigated in this study. EROD activity was increased upon addition of each compound. In CB-153 exposed animals, both EROD activity and P45O level responded more intensely than in CB-180 exposures. It appeared that both EROD activity and P45O level showed relatively more sensitive responses in the mixed compound exposures than in individual compound exposures. EROD activities assayed in Manila clams collected at different sites along the western coast of Korea showed a significant geographical difference, EROD activity of Manila clams collected near an industrial complex showed a seasonal change with the maximum occurring in April, possibly due to the fluvial input of pollutants at this time of the year. The suitability of EROD activity in the digestive gland of Manila clam as an early waming distress signal is discussed.