Inhibition of Cholinesterase Activity by Carbamate Insecticides

This study was carried out with the inhibition of the cholinesterase activity by carbamate insecticides in the chicken in vivo and in vitro. The optimum pH of cholinesterase was 8.0. The cholinesterase activity used the acetylcholin as substrate in plasma was 24.6 $\mu$mol/min/g protein. After oral administration with 0.32 mg/kg of BPMC as carbamate pesticide, the cholinesterase activity was inhibited to 60% of control after 15min in vivo. Then the recovery of cholinesterase activity followed to 97% of control after 12hr. I$_{50}$, such as concentration required for 50% inhibition of enzyme activity, of phenyl N-methylcarbamate were 329 $\mu\textrm{g}$/$\ell$ of XMC, 214 $\mu\textrm{g}$/$\ell$ of metolcarb, 111 $\mu\textrm{g}$/$\ell$ of BPMC, 107 $\mu\textrm{g}$/$\ell$ of propoxur and 104 $\mu\textrm{g}$/$\ell$ of isoprocarb. I$_{50}$ of aromatic N-methylcarbamate were 280 $\mu\textrm{g}$/$\ell$ of carbaryl and 114 $\mu\textrm{g}$/$\ell$ carbofuran.ran.

Carbamate계 살충제에 의한 Cholinesterase활성의 저해

Carbamate 농약에 대한 cholinesterase(ChE)활성저해 관계를 규명 하고자 in vivo와 in vitro 실험을 하였다. ChE의 최적 pH는 8.0이었다. 병아리 혈장의 ChE 활성은 기질로 acetylcholin를 사용할 경우 24.6 $\mu$mol/min/g protein이었다. in vivo에서 BPMC을 0.32 mg/kg 경구 투여한 15분 후에 ChE 활성이 60%까지 저해되었으며 그 후 12시간 후에 97% 까지 회복이 일어났다. in vitro에서 효소 활성이 50%로 저해되는데 필요한 농도인 I$_{50}$이 Phenyl N-methylcarbamate계에 XMC는 329 $\mu\textrm{g}$/$\ell$였고, metolcarb은 214 $\mu\textrm{g}$/$\ell$였다. BPMC는 111 $\mu\textrm{g}$/$\ell$, propoxur는 107 $\mu\textrm{g}$/$\ell$, isoprocarb는 104 $\mu\textrm{g}$/$\ell$이었다. Aromatic N-methylcarbamate계에 속하는 carbaryl의 I$_{50}$은 280 $\mu\textrm{g}$/$\ell$이었고, carbofuran 114 $\mu\textrm{g}$/$\ell$이었다.이었다.