Correlation between damping coefficients and externally injected currents in oscillations produced by lithium ions in frog skin.

Oscillations in the electrical parameters elicited by Li+ added to the mucosal side of frog skin in vitro were studied under different experimental conditions. The correlation between the damping coefficient and the size of the externally injected current was ascertained. The size of the overall epithelial resistance in NaCl-Ringer seems to be a good indicator of the qualitative behaviour of the skin in the presence of Li+: the higher the resistance the less probable the occurrence of oscillations. Addition of amiloride allowed the calculation of the electromotive force in Na+- and Li+-Ringer. Calculations of the 'total equivalent inductance' and 'total equivalent capacitance' of an oscillating skin were made using resistance values (R), damping coefficients (sigma) and frequency of oscillation (omega).