A Study on the Enzyme Activities of a Honeybee(Apis cerana F.) Associated with the Degradation of Some Insecticides.

살충제분해에 관여하는 동양종(東洋種)꿀벌의 효소활성(酵素活性)에 관(關)한 연구(硏究)

This study was conducted to investigate insecticide toxicities to a honeybee, Apis cerana F. being raised in Korea and its detoxifying enzyme activities. In order to determine the appropriate usage of insecticides, median effective dose and detoxifying enzyme activities to seven insecticides were observed. Various detoxifying enzymes, including microsomal oxidases, glutathione S-transferases, esterases, and DDT-dehydrochlorinase were assayed in the midguts of adult worker bees as the enzyme source. Of the insecticides used, $LC_{50}$ value in DDT treatment was the highest as 19ppm, and that in EPN treatment was the lowest as 0.75ppm. Sublethal exposures of honeybees to various insecticides had some effects on microsomal enzyme activities. Aldrin epoxidase activity was inhibited by malathion and demeton S-methyl treatment. N-demethylase activity was induced by carbaryl treatment. Of the glutathione S-transferases, aryltransferase(DCNB conjugation) activity was significantly induced by diazinon, and moderately induced by malathion. Of the esterases, ${\alpha}-NA$ esterase activity was moderately inhibited by malathion and permethrin. Carboxylesterase and acetylcholinesterase activity were not affected by the sublethal exposure of honeybee to the insecticides. Sublethal exposure of honeybee to the insecticides had no effect on DDT- dehydrochlorinase activity, except carbaryl, malathion and demeton S-methyl were inhibited.

동양종(東洋種)꿀벌 (Apis cerana F.)에 대(對)한 살충제(殺蟲劑)의 독성(毒性) 및 해독능력(解毒能力)을 조사(調査)하고 농약한계 사용량 결정에 기여하기 위하여 7가지 대표적인 살충제의 꿀벌에 대한 독성 및 해독효소의 활성을 조사하였다. 효소 활성은 해독효소로 알려진 microsomal oxidases, glutathione S-transferasecs, esterase와 DDT-dehydrochlorinase를 조사했고 성충(成蟲)일벌의 중장(中腸)을 사용하여 측정하였다. $LC_{50}$치의 측정 결과는 다음과 같다. 1. 공시 살충제중 DDT가 19ppm으로 독성(毒性)이 가장 낮았고 EPN이 0.75ppm으로 독성(毒性)이 가장 강(强)했다. 2. 준치사농도(準致死濃度)의 농약(農藥)이 성충(成蟲)일벌의 microsomal oxidase에 미치는 영향은 malathion 및 demeton S-methyl 처리가 aldrin epoxidase활성을 저해시켰고 N-demethylase활성은 carbayl 처리구에서 증대(增大)되었다. 3. Glutathione S-transferase(DCNB conjugation)활성은 diazinon과 malathion처리구에서 증대되었다. 4. Esterase는 malathion 및 permethrin처리구에서 ${\alpha}-NA$ esterase 활성(活性)의 저해(沮害)를 보였고 carboxylesterase와 AchE 활성은 거의 영향이 없었다. 5. DDT-dehydrochlorinase 활성은 carbaryl, malathion과 demeton S-methyl 처리구에서 저해를 보였다.