Kadous A, Matsumura F, Enan E
Department of Environmental Toxicology, University of California, Davis 95616.
J Environ Sci Health B. 1994 Sep;29(5):855-71. doi: 10.1080/03601239409372907.
Deltamethrin is a powerful neuroactive agent causing increased neurotransmitter release at the synapse. To understand the cause for such an action of this pyrethroid insecticide, we have studied its binding characteristics to the calcium channel by utilizing 3H-verapamil as a specific ligand. It was found that deltamethrin is capable of competing at the same binding site as 3H-verapamil. Also, it was found that nonlabeled verapamil could reduce the binding of 3H-deltamethrin (tested at 1 nM) to its binding site. The EC50 value of verapamil to displace 50% of 3H-deltamethrin was in the order of 0.3 microM, which coincides with the approximate KD value for this ligand to bind with calcium channels in the rat brain synaptosomal plasma membranes.
溴氰菊酯是一种强效神经活性剂，可导致突触处神经递质释放增加。为了解这种拟除虫菊酯杀虫剂产生此类作用的原因，我们利用3H-维拉帕米作为特异性配体研究了其与钙通道的结合特性。发现溴氰菊酯能够在与3H-维拉帕米相同的结合位点竞争。此外，还发现未标记的维拉帕米可以降低3H-溴氰菊酯（在1 nM下测试）与其结合位点的结合。维拉帕米置换50%的3H-溴氰菊酯的EC50值约为0.3 microM，这与该配体与大鼠脑突触体细胞膜中钙通道结合的近似KD值一致。
