Effects of lead exposure on blood electrical impedance spectroscopy of mice

Lead is a nonessential heavy metal, which can inhibit heme synthesis and has significant cytotoxic effects. Nevertheless, its effect on the electrical properties of red blood cells (RBCs) remains unclear. Consequently, this study aimed to investigate the electrical properties and the electrophysiological mechanism of lead exposure in mouse blood using Electrical Impedance Spectroscopy (EIS) in 0.01-100 MHz frequency range. Data characteristic of the impedance spectrum, Bodes plot, Nyquist plot and Nichols plot, and Constant Phase Element (CPE) equivalent circuit model were used to explicitly analyze the differences in amplitude-frequency, phase-frequency, and the frequency characteristics of blood in electrical impedance properties.

Compared with the healthy blood in control mice, the changes in blood exposed to lead were as follows: (i) the hematocrit decreased; (ii) the amplitude-frequency and phase-frequency characteristics of electrical impedance decreased; (iii) the characteristic frequencies (f₀) were significantly increased; (iv) the electrical impedance of plasma, erythrocyte membrane, and hemoglobin decreased, while the conductivity increased. (v) The pseudo-capacitance of cell membrane (CPE_Tm) and the intracellular pseudo-capacitance (CPE-Ti) were decreased.

Therefore, EIS can be used as an effective method to monitor blood and RBC abnormalities caused by lead exposure. The electrical properties of the cells can be applied as an important observation in the evaluation of the toxic effects of heavy metals.