Abstract
The effects of organophosphorus were examined with inhibition of the cholinesterase activity on tile chicken plasma in vivo and in vitro. The cholinesterase activity in chicken plasma determined by tile Ellman mettled was $23{\mu}mol$/min/g protein. After oral administration with 0.2 and 0.5 times of organophosphorus terbufos $LD_{50}$(1.81 mg/kg), cholinesterase activity were inhibited to 36% and 96% of control after 15min in vivo, respectively. After oral administration with 0.2 and 0.5 times of terbufos $LD_{50}$(1.81 mg/kg), then the recovery of cholinesterase activity followed to 99% and 56% of control after 11hr, respectively. Ki of phosphorodithioate and phosphorothioate with P=S was $74{\sim}322\;mole^{-1}min^{-1}$ in vitro. Ki of phosphate and phosphorothiolate with P=O was $13898{\sim}79610\;mole^{-1}min^{-1}$. Toxicology of organophosphorus with P=S was higher than that of organophosphorus with P=S by oxidation. $pI_{50}$ of phosphorodithioate and phosphorothioate with P=S was $21{\sim}102$ mg/L. $pI_{50}$ of phosphate and phosphorothiolate with P=O was $0.519{\sim}0.071$ mg/L. Enzyme-Inhibition method with cholinesterase was the rapid bioassay method to detect the organohpophorus pesticides in vitro.
유기인계 농약에 대한 cholinesterase(ChE)활성저해 관계를 규명 하고자 in vivo와 in vitro 실험을 하였다. 병아리 혈장의 ChE 활성은 $23{\mu}mol$/min/g protein이었다. in vivo에서 terbufos의 투여량을 $LD_{50}$의 0.2배(0.362 mg/kg)와 0.5배(0.905 mg/kg)로 투여하였을 경우, 투여 15분 후에 ChE 활성이 각각 36%와 96%까지 저해되었으며 그 후 회복이 일어난다. in vitro에서 유기인계의 P에 S가 결합된 P=S구조의 phosphorodithioate와 phosphorothioate의 Ki는 $74{\sim}322\;mole^{-1}min^{-1}$로 낮았다. 그러나 P에 S가 산화되어 O가 결합된 P=O구조의 phosphate와 phosphorothiolate의 Ki는 $13898{\sim}79610\;mole^{-1}min^{-1}$로 높았다. 따라서 P=S가 P=O로 산화됨으로서 ChE의 저해도가 커져서 독성이 강해짐을 확인하였다. phosphorodithioate와 phosphorothioate형의 $pI_{50}$값은 $21{\sim}102 mg/L(ppm)$ 이었다. 그러나 phosphate와 phosphorothiolate형의 $pI_{50}$값은 $0.519{\sim}0.071$ mg/L(ppm)이었다. 즉 ChE을 이용한 enzyme-inhibition(EI)법을 유기인계 농약의 정성적 검출에 이용한다면, P=O구조인 phosphate와 phosphorothiolate형은 1ppm이하 즉 ppb단위까지 정성적 검출이 가능하다.