Selective and asymmetric molecular transport across electroporated cell membranes
| Autor: | R D Astumian, Ephrem Tekle, P B Chock |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Cell Membrane Permeability
Population Video Recording Analytical chemistry CHO Cells Divalent Cell membrane Mice chemistry.chemical_compound Cricetinae Ethidium medicine Animals Humans Propidium iodide education chemistry.chemical_classification education.field_of_study Multidisciplinary Chemistry 3T3 Cells Electrophoresis Electroporation medicine.anatomical_structure Membrane Biophysics Calcium Ethidium homodimer assay Ethidium bromide Research Article HeLa Cells Propidium |
| Zdroj: | Proceedings of the National Academy of Sciences. 91:11512-11516 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.91.24.11512 |
| Popis: | Transport of a divalent cation (Ca2+) and three DNA indicators [ethidium bromide (EB), propidium iodide (PI), and ethidium homodimer (EthD-1)] across electroporated membranes of several mammalian cell lines was found to be selective and asymmetrical. In low salt medium, Ca2+ and EB were preferentially transported across the anodefacing cell membrane while PI and EthD-1 predominately entered at the site facing the cathode. In high salt medium, the entry site for Ca2+ and EB was reversed to the cathode-facing hemisphere while it remained unchanged for PI and EthD-1. In all these experiments, the observed transport patterns remained unaffected whether the dyes (or ion) were present during or added after the electroporating pulse. The data suggest that asymmetric pores are created on both sides of the membrane facing the electrodes, with smaller pore size (but greater in number) on the anode side and larger pores (with a lower population) on the cathode side. Furthermore, the rate of resealing of the membrane pores is significantly enhanced in high ionic strength medium, thus affecting the entry site. The asymmetric transport pattern is neither caused by electrophoresis induced by the externally applied electric field nor due to one-sided membrane breakdown as previously believed. |
| Databáze: | OpenAIRE |
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