Authors: Hongxia Liu Meiqin Yi Xueyan Shi Pei Liang Xiwu Gao
Publish Date: 2006/12/14
Volume: 33, Issue: 1, Pages: 29-34
Abstract
The substrate specificity of brain acetylcholinesterase AChE in adult Carassius auratus fish and its sensitivity to carbamate insecticides were investigated in vitro The results showed that the order of four substrates hydrolyzed by brain AChE in C auratus was acetylthiocholine iodide βmethylthiocholine iodide propionylthiocholine iodide butyrylthiocholine iodide and the maximum velocity V max of AChE hydrolyzing acetylthiocholine iodide ATCh was the highest among the four substrates and the V max values were 0067 and 0082 mmol min−1 mg−1 for male and female fish respectively But their Michaelis–Menten constants K m were the lowest only 0071 and 0072 mmol/l respectively Compared with other carbamate insecticides the sensitivity of brain AChE to carbofuran was the highest and the IC50 values were 104 × 10−6 mol/l for females and 117 × 10−6 mol/l for males The inhibitory tendencies of eserine methomyl and aldicarb to brain AChE were very similar and the percentage inhibition increased with time at the concentration of 1 × 10−6 mol/l The order of inhibition potential of the three inhibitors from the highest to the lowest was eserine aldicarb and methomyl
Keywords: