Dissociation of H + extrusion from K+ uptake by means of lipophilic cations

• DOI: 10.1111/j.1365-3040.1979.tb00772.x
• Publication Date: 2006-04-30T07:02:35Z
• Authors: M. BELLANDO; A. TROTTA; A. BONETTI; R. COLOMBO; P. LADO; E. MARRE
• Keywords: Fusicoccin

Abstract Dissociation of active H + extrusion (−ΔH ) from K uptake in pea and maize root segments was attempted by substituting the incubation medium with lipophilic cations assumed to enter cell passive, non‐specific, permeation through lipid component plasmalemma. Among compounds tested, tributylbenzylammonium significantly stimulated −ΔH absence other monovalent medium. This effect much more evident when experiment carried out presence fusicoccin, which strongly stimulates proton cation uptake, hyperpolarizes trans‐membrane electric potential these materials. Also tetraphenylphosphonium, dimethyldibenzylammonium hexylguanidine markedly FC‐promoted . Octylguanidine at a low concentration induced an early stimulation followed strong inhibition A complete lack additivity observed between effects that on extrusion. Lipophilic severely inhibited uptake. These data are interpreted as supporting view electric, rather than chemical, (namely, involving same carrier system) nature coupling influx.