次声作用后大鼠心肌细胞内钙离子变化与L型钙通道、Ca^(2+)-ATP酶及Na^+-K^+-ATP酶变化的关系

Relationship of Ca^(2+) ion concentrations with L-calcium channel expression, Ca^(2+)-ATPase and Na^+-K^+-ATPase in rat cardiac cells after infrasound exposure

目的:观察不同时间次声作用后大鼠心肌细胞钙离子变化与L型钙通道、Ca2+-ATP酶及Na+-K+-ATP酶变化的关系。方法:实验于2005-04/2006-08在解放军第四军医大学西京医院次声实验室完成。①实验分组:选择健康雄性SD大鼠32只,按随机数字表法分为4组,每组8只。次声暴露1,7,14d组(大鼠置于5Hz/130dB次声舱中,次声作用2h/次,1次/d),正常对照组(不予次声暴露)。②实验评估:测定大鼠心肌细胞内钙离子荧光强度,作为反映钙离子浓度的指标;测定L型钙通道mRNA的表达;测定Ca2+-ATP酶及Na+-K+-ATP酶活性。结果:①随着次声作用时间延长,大鼠心肌细胞钙离子浓度和L型钙通道mRNA的表达明显高于正常对照组(P<0.01)。②次声暴露1d组大鼠心肌细胞Ca2+-ATP酶及Na+-K+-ATP酶的活性显著高于正常对照组(P<0.01),次声暴露7d与14d组大鼠心肌细胞Ca2+-ATP酶及Na+-K+-ATP酶的活性显著低于正常对照组(P<0.01)。结论:5Hz/130dB次声引起大鼠心肌钙离子浓度的时间依赖性变化,这种变化可能与L型钙通道、Ca2+-ATP酶及Na+-K+-ATP酶的活性变化有关。

To observe the relationship of Ca^2＋ ion concentrations with the changes of L-calcium channel expression, Ca^2＋-ATPase and Na^＋-K^＋-ATPase in rat cardiac cells after infrasound exposures for different times. METHODS： The experiment was carded out in Infrasound Laboratory of Xijing Hospital of the Fourth Military Medical University of Chinese PLA from April 2005 to August 2006. ①Experiment grouping： A total of 32 male SD rats were randomly divided into 3 experimental groups （1, 7, 14 days of infrasound exposures） and control group （without infrasonic exposure）, each group containing 8 rats. Experimental groups exposed to infrasound of 5 Hz at 130 dB were put into the infrasonic chamber, 2 hours once daily.②Experiment evaluating： Ca^2＋ ion fluorescence intensity in rat cardiac cells was detected to reveal Ca^2＋ ion concentration, the expression of L-type calcium channel mRNA and the activities of Ca^2＋-ATPase and Na^＋-K^＋-ATPase were also determined. RESULTS： ①Compared with the control group, Ca^2＋ ion concentration and the expression of L-type calcium channel mRNA in cardiac cells were significantly increased in a time-dependent manner （P 〈 0.01）.②Compared with the control group, the activities of Ca^2＋-ATPase and Na^＋-K^＋-ATPase in 1-day infrasound exposure group were significantly increased （P 〈 0.01）, while the two indices were significantly declined in 7-day and 14-day infrasound exposure groups （P 〈 0.01）. CONCLUSION： Infrasound of 5 Hz at 130 dB can induce the changes of Ca^2＋ ion concentration, and these changes depend on the infrasound exposure time and are related to the changes of L-type calcium channel expression and changes of Ca^2＋-ATPase and Na^＋-K^＋-ATPase activities.