Zur Interpretation von Membranpotential-Konzentrationsbeziehungen in Pflanzenzellen

Summary According to the Hodgkin-Horowicz equation originally derived from an electrical analogues of the membrane, the potential drop Δ E induced by a sudden change of the external potassium ion concentration Δ K should be linear with respect to the concentration term In(l + Δ K/K 01 ). Analyzing 24 experimental investigations taken from the literature we found that in most cases the above relation does not hold. Taking into account the ionic strength of the medium a modified voltage-concentration relation is derived containing besides others the transport number TK of the Hodgkin-Horowicz equation. All the data taken from the literature agree very well with this modified relation. Some consequences and predictions are discussed.