Selective electrode for dibenzyl dimethyl ammonium cation as indicator of the membrane potential in biological systems.
The electrode sensitive to dibenzyl dimethyl ammonium (DDA+), which is considered to be an indicator of the membrane potential, was constructed by using tetraphenyl borone (TPB-) embedded in dichloroethane. Rapid and Nernstian responses were exhibited against DDA+ solutions ranging between 10(-2) and 3 - 10(-6) M in concentration. High selectivity for DDA+ was observed in the presence of various inorganis salts, ADP, ATP, oxidizable substrates and sugars. The electrode developed here was used to measure the DDA+ uptake in Streptococcus faecalis and the results agreed with those reported by Harold, F.M. and Papineau, D. ((1972) J. Membrane Biol. 8, 27-44 and 45-62). While they determined the DDA+ concentration in the medium by measuring the absorbance of the filtrate treated with the ion-exchangers, the electrode can measure directly the DDA+ concentration in the bacterial suspension without any any pretreatment. It was also shown that the electrode can measure the DDA+ uptake in mitochondria during energization.
D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D001692:Biological Transport; D008725:Bis-Trimethylammonium Compounds; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D004566:Electrodes; D013293:Enterococcus faecalis / Q000502:physiology; D007700:Kinetics; D008433:Mathematics; D008564:Membrane Potentials / Q000187:drug effects; D008566:Membranes / Q000187:drug effects / Q000502:physiology; D008722:Methods; D008930:Mitochondria, Liver / Q000502:physiology; D008954:Models, Biological; D051381:Rats; D012402:Rotenone / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
D008725:Bis-Trimethylammonium Compounds; D012402:Rotenone; D014634:Valinomycin; D000968:Antimycin A