Ma Qing, Wang Li, Zhang Hong-Bo, Chen Lin
Institute of Physiology and Pharmacology, Medical School of Ningbo University, Ningbo 315211, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2009 Nov;25(4):500-4.
To study the changes in dielectric properties of gastrocnemius isolated from rats subjected to intermittent hypoxia for 4 weeks at the frequency range of 40 Hz - 110 MHz.
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, spectrum of loss factor and conductivity imaginary part, as well as loss tangent.
Intermittent hypoxia could induce some changes, both relative permittivity (epsilon L, epsilon h) and permittivity increment deltaepsilon reduced, conductivity at low-frequency kappa L increased, conductivity at high-frequency kappa h reduced, and at the same time, the conductivity difference deltakappa 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.
Fall in dielectric properties and increase in the characteristic frequency in skeletal muscle were induced by intermittent hypoxic acclimation.
研究在40Hz - 110MHz频率范围内,对大鼠进行4周间歇性低氧处理后,其腓肠肌介电特性的变化。
采用低压舱对雄性Sprague-Dawley大鼠进行低氧模拟,将大鼠分为两组,即4周间歇性低氧组及其对照组。用安捷伦4294A阻抗分析仪测量离体腓肠肌的交流阻抗,并通过分析介电谱、科尔-科尔图、损耗因子谱和电导率虚部以及损耗角正切的介电数值特征,监测间歇性低氧对离体大鼠腓肠肌细胞介电特性的影响。
间歇性低氧可引起一些变化,相对介电常数(εL、εh)和介电常数增量δε降低,低频电导率κL升高,高频电导率κh降低,同时,电导率差值Δκ也降低。特征频率(f1、f2)升高。损耗因子峰值、电导率虚部峰值和损耗角正切峰值降低。
间歇性低氧适应可导致骨骼肌介电特性下降和特征频率升高。