Electrophoretic transport of T1+ in mitochondria.
The distribution of T1+ between rat liver mitochondria and the medium was studied; millimolar or smaller concentrations of T1+ were labeled with 204T1. The T1+ distribution responded to transient diffusion potentials in a way that indicated electrophoretic movements of T1+. The diffusion potentials were induced by efflux of K+ in response to addition of valinomycin to nonrespiring mitochondria suspended in a medium with low concentrations of K+ or by efflux of H+ induced by making the medium more alkaline in the presence of a protonophorous (proton-conducting) uncoupling agent. Changes in membrane potential induced by valinomycin were followed with the aid of safranine. T1+ brought about collapse of the diffusion potential. It is concluded that T1+ is able to penetrate the mitochondrial membrane electrophoretically.
D000818:Animals; D004058:Diffusion; D004594:Electrophysiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D013793:Thallium / Q000378:metabolism*; D014634:Valinomycin / Q000494:pharmacology
D014634:Valinomycin; D013793:Thallium; D011188:Potassium