间断性低氧对大鼠腓肠肌介电性能的影响

EFFECTS OF INTERMITTENT HYPOXIA ON DIELECTRIC PROPERTIES OF RAT GASTROCNEMIUS

目的:在40 Hz～110 MHz频率范围观察间断性低氧暴露4周大鼠离体腓肠肌细胞介电性能的改变。方法:采用低压氧舱建立模拟低氧模型,雄性SD大鼠随机分为间断低氧组和正常对照组。利用Agilent 4294A阻抗分析仪测量了离体大鼠腓肠肌的交流阻抗,通过频域介电谱、Cole-Cole图、介电损耗因子频谱、电导率虚部频谱和介电损耗角正切频谱的数据分析,观察间断性低氧暴露对大鼠离体腓肠肌细胞介电性能的影响。结果:间断性低氧暴露4周大鼠腓肠肌的介电常数(εL,εh)降低,介电增量Δε减小,绝缘性降低;低频电导率κL升高,高频电导率κh降低,电导率增量Δκ降低;特征频率(f1,f2)增加;介电损失峰值ε"peak、电导率虚部峰值κ"peak和损耗角正切峰值tgδpeak均降低。结论:间断性低氧暴露致骨骼肌细胞介电性能降低,但其特征频率增加。

Aim： To study the changes in dielectric properties of gastrocnemias isolated from rats subjected to intermittent hypoxia for 4 weeks at the frequency range of 40 Hz- 110 MHz. Methods： Hypoxia was simulated by low-pressure chamber in male Sprague-Dawley rats, the rats were divided into two groups, that is, 4 weeks of intermittent hypoxia group and its control. The AC impedance of isolated gastrocnemius is measured with the Agilent 4294A impendance analyzer, and effects of intermittent hypoxia on dielectric properties of cells in isolated rat sural muscle were monitored by analyzing the dielectric numerical characters of the dielectric spectroscopy, the Cole-Cole plots, spectntm of loss factor and conductivity imaginary part, as well as loss tangent. Results： Intemtittent hypoxia could induce some changes, both relative permittivity （εL,εh） and permittivity increment △ε reduced, conductivity at low-frequency teL increased , conductivity at high-frequency κh reduced, and at the same time, the conductivity difference △κ also reduced. The characteristic frequency（f1 ,f2） increased. Peak of loss factor, the peak of conductivity imaginary part and the peak of loss tangent reduced. Conclusion： Fall in dielectric properties anti increase in the characteristic frequency in skeletal muscle were induced by intermittent hypoxic acclimation.