【摘要】 为探讨A计权声压级在65 d B以下的变压器噪声暴露对SD大鼠神经递质和海马区神经组织可能的影响,采样了某1 000 k V变压器噪声作为实验声源,在隔声实验箱中重播。选取96只健康成年(6月龄)SD大鼠随机均分为暴露组S1、暴露组S2和对照组C。暴露组S1、S2分别给予A计权昼夜等效声压级Ldn为60 d B、65 d B的变压器噪声,连续暴露35 d时间,对照组C在相同条件下饲养,无噪声暴露。噪声暴露结束后,测定了SD大鼠主要神经递质的含量,观察了SD大鼠中枢神经系统海马区神经元及突触超微结构,检测了SD大鼠脑部海马区主要神经元蛋白表达水平。研究结果表明:采用高效液相色谱–荧光法测定的暴露组SD大鼠血浆中谷氨酸(Glu)、γ–氨基丁腺素(GABA)、5–羟色胺(5–HT)和多巴胺(DA)等主要神经递质的含量与对照组相比均无显著差异(概率P>0.05);利用透射电子显微镜观测的SD大鼠中枢神经系统海马区神经元超微结构和海马区突触形态超微结构与对照组相比均无显著差异(P>0.05);采用蛋白质印迹法(Western blot)检测的SD大鼠脑部海马区钙调神经磷酸酶(Ca N)A亚基、钙离子/钙调素依赖性蛋白激酶(Ca MKII)α亚基等主要神经元蛋白表达水平与对照组相比均无显著差异(P>0.05);变电站站界的变压器噪声A计权声压级昼间不超过65 d B,夜间不超过55 d B,以500 Hz以下低频分量为主,高频分量低且衰减快,这种稳定的噪声比交通和工厂噪声低很多,不足以引起SD大鼠神经递质和海马神经组织结构的变化。因此Ldn为60 d B、65 d B的变压器噪声暴露35 d时间对成年SD大鼠的神经递质和神经组织均无明显影响。更多还原

【Abstract】 To study the possible effect of the transformer noise exposure below 65 d B, as A weighting sound pressure level, on the neurotransmitter and nervoustissue in hippocampus of SD rats, we experimentally investigated the transformer noise in a 1 000 k V UHV substation, as noise experiment source. The noise samples were replayed in the noiseproof box. 96 SD rats were grouped randomly into noise exposed group S1(32), S2(32), and control group C(32). The noise exposed group S1 was exposed to the 60 d B and the exposed group S2 was exposed to the 65 d B transformer noise for consecutively 35 days, the transformer noise was diurnal equivalent as A weighting sound pressure level(Ldn). The control group was housed to the same conditions without the transformer noise.The back noise of the experimental box is less than 35 d B. The neurotransmitter and nervoustissue of the hippocampus area in SD rats were determined after a 35-day noise exposure, as well as the expression levels of Ca N and Ca MKII subunit. Neurotransmitter was determinated by high-performance liquid chromatography. Results revealed no significant difference(P>0.05) between exposed group and control group with Glu, GABA, 5–HT and DA. Ultrastructure of neurons and synapses in hippocampus of SD rats were observed by transmission electron microscopy. No significant difference(P>0.05) was found in the neuronal ultrastructure and synaptic ultrastructure. Western blot was used to detect the expression levels of Ca N and Ca MKII subunit. And there was no significant difference(P>0.05) in protein expression assay(expression of Ca N A and Ca MKII α subunit). Exposure of the 60 d B and 65 d B transformer noise in 35 days does not affect the SD rat hippocampus neuronal apoptosis and expression of Ca N and Ca MKII. The transformer noise about the substation is less than 65 d B daytime as a weighting sound pressure level, and 55 d B at night. The main frequency component is below 500 Hz. High frequency components are low and decaying fast. This steady noise is much lower than traffic and factory noise which is not enough to cause changes in neurotransmitter and hippocampal tissue structure in SD rats. In conclusion, 60 d B and 65 d B of transformer noise(Ldn) have no effect on the neurotransmitter and nervoustissue in hippocampus of SD rats.更多还原