The Effect Of Aircraft Noise Exposure On Apoptosis And Fas Protein Expression In Rat Brain

ObjectiveTo analyse the effect of aircraft noise exposure on Apoptosis and Fas protein expression in rat brain.MethodsSixteen SD rats were divided randomly to four groups and were postexposed in the environmental physics laboratory of Zhejiang University. Hang-zhou Xiao-shan International Airport were sampled as the exposure noise source. The four groups are: non-nosie exposure 60days group(N1), non-nosie exposure 90days group(N2), noise exposure 60days group(N3) and noise exposure 90days group(N4). The former two are control group, and later two are experimental group. The expression of Fas proteins in rat hippocampus were detected by using immunohistochemical method, and apoptosis as revealed by TUNEL staining. Use Image-Pro Plus6.0 software to analyse the Integrate Optical Density(IOD) of positive expression area. And we also observe the micro change of rat hippocampus neurons through transmission electron microscope.ResultsThe IOD of Fas expression inN1,N2 group are:2.67±1.67×103 and 3.03±2.18×103. These two groups showed no significant differences(P>0.05). The IOD of TUNEL expression in N1,N2 group are:44.10±1.67 and 51.75±10.90. These two groups also showed no significant differences(P>0.05).The IOD of Fas expression in N3,N4 group are:34.29±12.60×103 and 20.54±5.69×103. These two groups showed no significant differences(P>0.05), but when compared respectively to N1,N2 group the IOD are significantly upgraded(P<0.05). The IOD of TUNEL expression in N3,N4 group are:96.43±20.48 156.56±22.37. These two groups also showed no significant differences(P>0.05), when compared to respectively to N1, N2 group the IOD are also significantly upgraded(P<0.05).Through transmission electron microscope we find that when noise exposure time lasted for 60 days and 90 days, neurons of hippocampus in control group are normal, synaptic clefts of hippocampus area are clear. However, the neurons of hippocampus in experimental group began to apoptosis, synapse morphology alters, synaptic clefts of hippocampus are vague, chromatin aggregates and synaptic vesicles are not clear.ConclusionChronic noise expose can induce neuron apoptosis and the up-regulation of Fas protein expression in rat hippocampus.The up-regulation of Fas protein expression in rat hippocampus indicating that it may not be an possible way in neuron apoptosis.