Abstract
Electric field pulses, applied to densely packed pellets of Chinese hamster ovary (CHO) cells of mean radius āc
= 7.5 ± 0.7 μm, cause major electric conductivity changes, described by three kinetic normal modes. The first mode reflects Wien effects of ionic atmosphere perturbations and ion pair dissociations (cell surfaces). Using Maxwell’s conductivity equation, the second and third mode are converted to the respective membrane conductivity modes. Electrothermodynamic analysis in terms of structural transitions from closed (C) to porated (P) membrane states of very different lifetimes, according to the scheme (C ⇌ C1)
⇌
(P2
⇌ P3), yields the mean pore radii 2
= 1.00 ± 0.05 nm (P2) pores and 3
= 1.5 ± 0.1 nm (P3) at T
= 293 K (20 °C). The relaxation time τ2
(P2-formation) reflects the rate limiting step (C ⇌ C1), associated with the activation dipole moment of Δm1
= 63 × 10−30 C m (or 19 Debye units), suggesting orientational changes of dipolar