Intracellular binding of spin-labeled amiloride: An alternative explanation for amiloride's effects at high concentration
| Autor: | Charles J. Costa, Leonard B. Kirschner, Edward J. Cragoe |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Epithelial sodium channel
Trout Physiology Intracellular pH Clinical Biochemistry Mitochondria Liver Amiloride Cyclic N-Oxides chemistry.chemical_compound medicine Animals Cell Nucleus Chemistry RNA DNA Cell Biology Hydrogen-Ion Concentration Membrane transport Kinetics Liver Biochemistry Nucleic acid Intracellular medicine.drug |
| Zdroj: | Journal of Cellular Physiology. 130:392-396 |
| ISSN: | 1097-4652 0021-9541 |
| DOI: | 10.1002/jcp.1041300312 |
| Popis: | Amiloride, an important inhibitor of Na+ transport and Na+/H+ exchange, has been used in nontransporting tissues to investigate the relationship between ionic fluxes or intracellular pH change and proliferative or synthetic events. Reports that amiloride is permeant and had direct effects on intracellular processes have led us to investigate the possibility that amiloride binds intracellularly to nuclei, mitochondria, and to purified nucleic acids. Using a nitroxide spin-labeled derivative of amiloride (ASp) and electron paramagnetic resonance (EPR) spectroscopy, we have demonstrated that nuclei and mitochondria isolated from trout liver bind significant amounts of ASp especially at the high amiloride concentrations (approximately mM) commonly used to inhibit proliferative events. While the chemical component responsible for ASp binding in these organelles was not identified, native DNA binds significant amounts of ASp whereas single stranded DNA and RNA bind much less. When these observations are taken together with reports of amiloride's direct action on cellular processes, they support the possibility that some of the effects attributed to inhibition of a transport event are caused by amiloride directly. |
| Databáze: | OpenAIRE |
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