Modulation in Acetylcholinesterase of Rat Brain by Pyrethroids In Vivo and an In Vitro Kinetic Study
Modulation in Acetylcholinesterase of Rat Brain by Pyrethroids In Vivo and an In Vitro Kinetic Study
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拟除虫菊酯对大鼠脑乙酰胆碱酯酶的体内调节和体外动力学研究
DOI：
10.1046/j.1471-4159.1995.65052259.x
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发表时间：
1995
影响因子：
4.7
通讯作者：
K. J. Jagannatha Rao
中科院分区：
文献类型：
--
作者：
G. V. Rao;K. J. Jagannatha Rao
摘要：在体内和体外研究了两种拟除虫菊酯——氯菊酯（PM）和氯氰菊酯（CPM）对大鼠脑乙酰胆碱酯酶（AChE）的调节作用。胃插管后4、8和12小时，PM抑制大鼠大脑所有区域（大脑皮层、小脑、纹体、脑干、海马和下丘脑）的AChE活性，而CPM则升高体内酶活性。底物依赖性酶动力学研究表明，PM 和 CPM 表现为混合型抑制剂，米氏常数 (Km) 和最大速度 (Vmax) 值的变化证明了这一点。这表明 PM 和 CPM 与底物乙酰胆碱在疏水亚位点相互作用，并且可能能够同时与酶结合。
Abstract: The modulation in acetylcholinesterase (AChE) of rat brain by two pyrethroids—permethrin (PM) and cypermethrin (CPM)—was studied both in vivo and in vitro. PM inhibited AChE activity in all regions of the rat brain (cerebral cortex, cerebellum, corpora striata, brainstem, hippocampus, and hypothalamus) at 4, 8, and 12 h after gastric intubation, whereas CPM elevated the enzyme activity in vivo. Substrate‐dependent enzyme kinetic studies have shown that PM and CPM behave as mixed‐type inhibitors, as evidenced by alterations in both Michaelis‐Menten constant (Km) and maximal velocity (Vmax) values. This indicates that both PM and CPM and substrate acetylcholine interact at hydrophobic subsites and may be able to bind simultaneously to the enzyme.