A translation of Maurice Philippson's "Principles of the Electrical Resistance of Living Tissue"

TL;DR

This study measures the electrical impedance of living tissues like potato and guinea pig muscle across a range of frequencies, revealing how cell membranes and protoplasm resistances change with biological states.

Contribution

It provides a detailed analysis of tissue impedance behavior and models cell membranes as capacitors, offering insights into tissue electrical properties during different physiological conditions.

Findings

Membrane impedance decreases with increasing frequency.

Membrane resistance drops after death in guinea pig tissue.

Protoplasm resistance decreases during potato germination.

Abstract

The impedance of one cubic centimeter of living tissues of potato and guinea pig were measured from 500 Hz to 3 MHz. In general, the magnitude of the impedance was found to monotonically decrease with increasing frequency. This implies that the membrane of each cell in the tissue acts like a capacitor, which is in parallel with a membrane resistance. The membrane resistance and capacitance together are in series with a protoplasm resistance. Experimentally, it was observed that after the guinea pig died, the membrane resistance of its muscle decreased from 1.49 to 0.79 kilo-ohm while the protoplasm resistance remained around 0.11 kilo-ohm. By contrast, when the potato started to germinate, the protoplasm resistance decreased from 0.25 to 0.10 kilo-ohm, while its membrane resistance remained around 4 kilo-ohms.