吡虫啉对原代培养的大鼠海马神经元NO含量和NOS活性的影响

Effects of Imidacloprid on Content of NO and Activity of NOS in Primary-cultured Rat's Hippocampus Neurons

目的 研究新型农药吡虫啉对原代培养的大鼠海马神经元细胞培养液内NO(一氧化氮 )含量和细胞内NOS(一氧化氮合酶 )活性的影响。方法 原代培养的大鼠海马神经元成熟后 ,分组加入不同浓度的吡虫啉进行染毒 ,于染毒后 12h、2 4h、4 8h分别在相差显微镜下观察其形态学改变 ,并测定细胞死亡率 ,细胞培养液内NO含量及细胞内NOS的活性。结果 与DMSO对照组相比 ,除 0 ,10 -6mol/L吡虫啉组外 ,随染毒浓度增加 (10 -5～ 10 -3 mol/L)和染毒时间延长 ,出现细胞肿胀、胞体内颗粒增多和突起断截等改变 ,细胞间网络也变稀疏 ;细胞死亡率和细胞培养液NO含量在作用 2 4h后增加 (P <0 0 5 ) ,作用 4 8h继续增加 (P <0 0 1)。细胞内NOS活性在作用 12h于 10 -3 mol/L组首先出现升高 (P <0 0 1) ;作用 2 4h ,10 -5～ 10 -4mol/L组也升高 (P <0 0 1) ,10 -3 mol/L继续升高 (P <0 0 1) ;作用 4 8h ,各浓度组吡虫啉的细胞内NOS活性与 2 4h时相比无明显变化。结论 10 -5～ 10 -3 mol/L浓度的吡虫啉可引起原代培养的大鼠海马神经元细胞培养液内NO含量和细胞内NOS活性的升高 ,这可能与其神经毒性作用有关。

Objective To study the effect of new-typed pesticide imidacloprid on the content of NO(nitric oxide) in nutrient solution and the activity of NOS (NO synthase) in primary-cultured rat, hippocampus neurons.Methods To poison mature primary-cultured rat's hippocampus neurons with imidacloprid of different concentration; then to observe the morphological change under phase difference microscope to determine cell mortality,the content of NO in nutrient solution and the activity of NOS respectively at time of 12h,24h and 48h after poisoning.Results Compared with DMSO control group, there are following changes for each group apart from groups of zero and 10 -6 mol/L imidacloprid with increase of poisoning concentration (10 -5 -10 -3 mol/L) and prolonging of poisoning time.Hippocampus neurons become swell,the intracellular granules increase,the axon and dendrite break or even loss,the intercellular network also becomes sparser.The cell mortality and the content of NO increase after poisoning for 24h ( P <0.05),and they increase much more at time of 48h ( P <0.01).The activity of intracellular NOS of 10 -3 mol/L imidacloprid group increases at time of 12h( P <0.01),and it becomes higher at 24h ( P <0.01),that of 10 -5 -10 -4 mol/L imidacloprid groups also increases at time of 24h( P <0.01).And there is no obvious change for the activity of NOS of every group between time of 24h and 48h.Conclusion Imidacloprid with concentration range from 10 -5 mol/L to 10 -3 mol/L can result in increase of the content of NO in nutrient solution and the activity of NOS in primary-cultured rat's hippocampus neurons,which may be related to its neurotoxic effect.