Abstract
Cytochrome P45O (CYP) contents and 7-ethoxyresorufin-O-deethylase (EROD) activity were determined in hepatic microsome of olive flounder (Paralichthys olivaceus) exposed to tributyltin chloride (TBTC), tributyltin oxide (TBTO), and triphenyltin chloride (TPTC). In addition, effects of in vivo (intraperitoneal injection of 7.5 mg $kg^{-1}$ BW) exposure of flounder to TPTC on CYP, NADPH cytochrome c reductase, NADH cytochrome b5 yeductase and EROD levels were measured. In in vitro exposure of hepatic microsome to organotins, TBTC, TBTO and TPTC reduced CYP contents and inhibited EROD activity. The TPTC was the strongest inhibitor, which is followed by TBTO and TBTC. The degree of inhibition, especially EROD acitivity, depended on the exposure duration. In addition, all the target enzymes in flounder were inhibited by TPTC with the in vivo exposure to TPTC. As EROD activity was the most sensitive to the inhibitions and demonstrated good reproducibility of the results, it could be used as a helpful tool toy monitor effects of organotin compounds on mixed funciton oxygenase system in marine fish.
유기주석화합물인 tributyltin chloride (TBTC), tributyltin oxide (TBTO)와 triphenyltin chloride (TPTC)를 넙치 간장으로 만든 미크로좀에 in vitro적으로 노출시켜서 이들 화합물의 대사에 관여하는 mixed function oxidase (MFO) 중 cytochrome P450 (CYP) 농도와 7-ethoxyresorufin deethylase (EROD) 활성의 변화를 조사하였으며, 또한 in vivo 실험에서는 TPTC를 넙치에게 복강주사(7.5 mg $kg^{-1}$ BW)하여 간장의 MFO (CYP농도, NADPH cytochrome c 환원효소 활성, NADH chtochrome b5 환원 효소 활성, EROD 활성) 반응을 경시적으로 조사하였다. 그 결과, in vitro에서는 TBTC, TBTO 및 TPTC가 모두 CYP 농도와 EROD 활성을 저해하였으며, 저해력은 TPTC가 가장 컸고 이어서 TBTO, TBTC의 순이었다. 유기주석화합물의 노출농도와 노출시간과 비례하면서 저해정도가 커졌으며, 특히 EROD활성의 저해는 노출농도에 크게 의존적이었다. 그리고 in vivo실험에서도 유기주석 화합물은 CYP농도, NADPH cytochrome c 환원효소 활성, NADH cytochrome b5 환원효소 활성, EROD 활성을 억제하였다. EROD 활성은 오염물질에 의한 반응이 민감하고 재현성도 있어 바람직한 측정지표로 이용될 수가 있을 것이다.
