Synergistic effects of pesticides on detoxifying enzyme activity of carp(Cyprinus carpio L.)

농약의 협력작용으로 인한 잉어의 해독효소 활성의 변화

This study was performed to investigate detoxifying enzyme activities of carboxylesterase(CE), glutathione S-transferase(GST) and lactate dehydrogenase(LDH) at variable toxicity levels in fresh water fish, carp(Cyprinus carpio L.). The carp was exposed to single and combined pesticides of IBP, isoprothiolane and cartap for 48 hr at sublethal doses, $LC_{10}$ and $LC_{26}$. The detoxifying enzyme activities were assayed for the liver, head and gut of the carp. The enzyme activities we discovered were as follows: Both activities of CE and GST were increased at the sublethal doses but were declined by increasing doses. In the gut, we found that the CE activity had high levels in the treatment groups of isoprothiolane+IBP and isoprothiolane+cartap. In the head, the CE activity had high levels in the treatment groups of cartap, IBP and isoprothiolane. However, the GST activities were inconsistent in the head and gut of the fish. Also, the GST activity was declined by increasing protein contents. The highest LDH activity was shown in the isoprothiolane treated fish, while the lowest activity was observed in the isoprothiolane+cartap treatment.

참잉어에 대한 해독효소 활성을 협력작용을 갖는 농약을 공시하여 조사하였고 잉어의 각 조직별 효소활성도 조사하였다. 협력작용을 갖는 약제의 독성증가에 따른 효소활성은 carboxylesterase와 GST 모두 준치사 농도에서는 활성의 증가를 보였으나 독성이 증가함에 따라 활성이 감소하였다. Carboxylesterase의 활성은 IBP와 isoprothiolane과의 협력작용으로 인해 현저한 감소를 보였으며 GST 활성 또한 isoprothiolane의 IBP, cartap과의 협력작용으로 인해 감소를 나타냈다. 한편 각 조직별 효소활성의 경우, carboxylesterase는 단일약제 처리시 공시어의 간(肝)에서, 혼합약제 처리시 장(腸)에서 그 활성이 높았으며 GST의 조직별 활성은 약제의 처리양상과는 관계없이 다양한 효과를 보였다. HPLC 방법에 의한 LDH의 활성은 isoprothiolane 단일처리구에서 활성이 가장 높았고 isoprothiolane+cartap 혼합처리구와 cartap 단일처리구에서는 가장 낮았다.