小鼠体温对体积描记箱内压力变化的影响

Effects of mice body temperature on pressure inside plethysmograph

目的:观测麻醉小鼠在体积描记箱内引起的温度及压力的变化过程,探讨该压力变化对小鼠呼吸的影响。方法:首先比较麻醉小鼠和死亡小鼠引起的整体体积描记箱内温度和压力变化;然后,将麻醉小鼠置入双室体积描记箱的躯体室,同步测量及观察躯体室与头室内温度和压力变化;最后,比较2种不同躯体体积描记法测量(一个描记箱保持对外密封而另一个体积描记箱则每2 m in内对外开放1 m in)描记箱内麻醉小鼠的呼吸频率和呼吸幅度变化。结果:麻醉小鼠使描记箱内温度和压力在6 m in内分别上升了1.18℃和2.710 mmHg,死亡小鼠使温度和压力分别升高了1.17℃和2.671 mmHg,两者比较无显著性统计学差异(P>0.05)。双室体积描记法的躯体室内温度和压力在20 m in内分别升高了1.92℃、5.554 mmHg,高于头室的0.09℃、0.627 mmHg(P<0.001)。密封躯体体积描记箱内小鼠的呼吸频率由125.04次/m in上升至168.45次/m in(P<0.001),呼吸引起的压力变化幅度由1.090 mmHg下降为0.883 mmHg(P=0.009);而开放躯体体积描记箱内小鼠的呼吸频率在120次/m in左右,呼吸时压力变化的振幅在1 mmHg左右,不同时间观察点间无显著性统计学差异(P>0.05)。结论:压力型整体体积描记箱内温度及压力升高主要来源于小鼠体温,而升高的描记箱内压力可影响小鼠的呼吸频率和潮气量。

Objective:To observe temperature and pressure changes inside plethysmograph produced by body temperature of anesthetized mice.Methods:The temperature and pressure changes inside whole body plethysmograph generated from anesthetized mice were compared with those from dead mice.The temperature and pressure changes inside body chamber and head chamber of double-chamber with anesthetized mice in body chamber were synchronously measured.The respiratory frequencies and amplitudes of mice inside two kinds of head-out plethysmographes were synchronously measured.One of these two plethysmograhes kept sealed all the time and the other was opened to the atmosphere for 1 min every 2 min.Results:Temperature and pressure of air in the anesthetized mice chamber increased 1.18℃ and 2.710 mmHg within 6 min,and data from dead mice were 1.17℃ and 2.671 mmHg.There were no significant differences between these two groups.The temperature inside body chamber increased 1.92℃ in 20 min and the pressure was 5.554 mmHg,which were significantly higher than those of head chamber(0.09℃ and 0.627 mmHg).The respiratory frequencies of mice in the sealed head-out plethysmograph increased from 125.04 per min to 168.45 per min,and amplitudes of pressure changes generated from mice breath decreased from 1.090 mmHg to 0.883 mmHg.Significant differences occurred between different observation time points.Meanwhile respiratory frequencies in the open head-out plethysmograph were around 120 per min and amplitude of pressure changes kept about 1 mmHg.There were no significant differences between different time points.Conclusion:Increase of temperature and pressure inside pressure whole-body plethysmograph are mainly from body temperature of mice,and the increased pressure significantly influences respiration of mice.