神经递质3H-去甲肾上腺素释放与家蝇对拟除虫菊酯抗性的关系

在用K⁺去极化条件下，研究了溴氰菊酯和氯菊酯分别对敏感、抗溴氰菊酯和抗氯菊酯家蝇Musca domestica 品系脑突触体释放神经递质去甲肾上腺素的影响。结果表明：在用K⁺去极化后，神经递质去甲肾上腺素的释放在抗溴氰菊酯和抗氯菊酯家蝇品系中比敏感品系分别下降47.0%和51.0%；当用10^-5 mol/L溴氰菊酯预处理家蝇脑突触体，用K+去极化后对敏感、抗溴氰菊酯和抗氯菊酯家蝇品系释放去甲肾上腺素的加强作用分别提高80.3%、26.5%和70.5%；用10^-5 mol/L氯菊酯预处理3个家蝇品系的突触体对去甲肾上腺素释放均无加强作用。由此表明，家蝇对溴氰菊酯的抗性是与Na+通道的亲和性降低有关，而氯菊酯的抗性与Na+通道的亲和性关系不大。

Relationship between the release of 3H-norepinephrin and the pyrethroid-resistance in houseflies(Musca domestica)

The release of 3H labeled norepinephrin was used to assess the effect of selected neurotoxins on synaptosomes from brains of the susceptible (SP),deltamethrin resistant(Del R) and permethrin resistant(2Cl R) houseflies. A reproducible release of 3H neurotransmitter was evoked by pulsed depolarization in the presence of elevated K (55 mol/L). The enhanced 3H norepinephrin release from housefly synaptosomes of Del R and 2Cl R reduced by 47 0% and 51 0% respectively in comparison with that from the susceptible strain. The synaptosomes pretreated with 10 -5 mol/L deltamethrin in SP, Del R and 2Cl R strains resulted in 80 3%,26 5% and 70 5% enhancement of 3H neurotransmitter release during pulsed depolarization, respectively. These results were consistent with the hypothesis that knocked down resistance is most likely due to a decreased affinity of the voltage gated sodium channel for deltamethrin. However, the resistance against permethrin showed little effect on synaptosomal efflux of 3H norepinephrin.