次声对大鼠心率与血压影响的实验观察

目的:观察大鼠暴露于8Hz,130dB及90dB次声不同时间后血压及心率的变化。方法:将90只雄性大鼠随机为对照组、90dB暴露组及130dB组各5组(n=6),在1,7,14,21和28d暴露期间施以次声,2h/d,采用颈动脉插管法记录大鼠血压与心率。结果:与对照组比较,90dB1d组及130dB1d组大鼠心率均加快(P<0.01),7,14,21,28d组无显著变化(P>0.05);130dB1d组心率快于90dB1d组(P<0.05)。90dB及130dB的1,14,21,28d组左室收缩压增加(P<0.01),90dB7d组无显著变化,而130dB7d组较90dB7d组增加(P<0.05)。90dB及130dB的1,7,14d组大鼠左室舒张压无显著变化(P>0.05),而21,28d组增加(90dB组P<0.05;130dB组P<0.01),130dB组增加较90dB组快。结论:次声对大鼠血压及心率有一定影响,与次声作用时间和声压级水平有关。

Experimental study on effects of infrasound on heart rate and blood pressure of rats

Objective: To observe effects of infrasound on blood pressure(BP) and heart rate(HR) of rats. Methods: Ninety male Sprague-Dawley rats were randomly divided into five control groups,five 90 dB infrasound groups and five 130 dB infrasound groups(all n=6).The rats were exposed to infrasound for 1,7,14,21 and 28 d, 2 h daily. BP and HR of rat were observed through intubation to carotid artery of rats. Results: Compared with control groups,the HR of the 90 dB 1 d and 130 dB 1 d groups increase significantly(P<0.01),while the HR of 90 dB and 130 dB at 7,14,21 and 28 d groups did not increased significantly(P>0.05),The HR of 30 dB 1 d group was faster than that of 90 dB 1 d group(P<0.01).The LVSP of 90 dB 7 d group did not increase significantly(P>0.05),while that of 130 dB 7 d group,90 dB and 130 dB at 1,14,21 and 28 d groups increased significantly(P<0.01). Compared with the groups of 90 dB, the LVSP of 130 dB at 7,14,21 and 28 d groups increased significantly (P<0.05) . The LVDP of 90 dB and 130 dB at 1, 7, 14 d groups did not change significantly (P>0.05), but the LVDP of 90 dB and 130 dB at 21 and 28 d groups increased significantly ((90 dB) groups P<0.05;130 dB groups P<0.01).Compared with the groups of 90 dB, the LVDP of 130 dB at 21 d and 28 d groups was higher significantly (P<0.05). Conclusion: Infrasound affects HR and BP of the rats to some extent, which depends on infrasound exposure time and pressure level of infrasound.