白噪声暴露致豚鼠心脏功能损伤作用

Effects of white-noise on heart function of guinea pig

目的探讨噪声暴露对心脏的影响。方法将豚鼠分别置于95和100 dB的白噪声环境中,4 h/d,连续14 d后,测量心电图(ECG),观察光镜和电镜下心肌结构的变化,测定心肌组织丙二醛(MDA)含量和血清乳酸脱氢酶(LDH)活性。结果噪声暴露后,豚鼠ECG变化明显,HR明显加快、P-R间期缩短、P波电压增大、T波电压降低等。100 dB暴露组心肌超微结构损伤较严重,心肌组织MDA含量和血清LDH活性分别为(1.645 8±0.050 0)nmol/(mg.prot)和(3 590.06±905.53)U/L,与正常对照组比较,均明显升高(P<0.01)。95 dB暴露组损伤较轻,MDA含量和LDH活性分别为(1.377 5±0.157 3)nmol/(mg.prot)和(2 651.88±487.99)U/L。结论一定剂量的噪声暴露可引起豚鼠心功能紊乱,心肌的形态结构发生病理性改变。

Objective To investigate the effect of white-noise on heart function of guinea pig. Methods The guinea pigs were exposed to white-noise of 95 dB or 100dB ,4 hr a day for 14 days. Then the electrocardiogram （ECG）, the changes of myocardium structure, the content of malonaldehyde（ MDA）, and the activity of lactic acid（LDH） were detected. Results After noise exposure,the ECGs of guinea pigs changed obviously with increased heart rate,decreased P-R duration, augmented P wave amplitude, reduced T wave amplitude. The differences were significant. Compared with the control group, ultrastructure alteration of myocardium in 100dB noise-exposed group was serious and the MDA content and LDH activity were increased significantly（ P 〈0.01 ）. The damage of 95dB noise-exposed group was less serious compared to the 100dB noise-exposed group. Conclusion The results suggested that noise exposure induced guinea pig＇ s cardiac function disorder,myocardium ultrastructure alteration,and the extent of heart changes was related with the intensity of noise exposure.