Lipid vesicle-mediated alterations of membrane cholesterol levels: Effects on Na+ and K+ currents in squid axon
| Autor: | Joy A. Steele, Malcolm S. Brodwick, Douglas C. Eaton, Mark J. Poznansky |
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| Rok vydání: | 1981 |
| Předmět: |
Physiology
Membrane lipids Biophysics Phospholipid Biological Transport Active Membrane Potentials Cell membrane Membrane Lipids chemistry.chemical_compound Mole medicine Animals Phospholipids Membrane potential Liposome Cholesterol Vesicle Cell Membrane Sodium Decapodiformes Cell Biology Axons medicine.anatomical_structure Biochemistry chemistry Liposomes Potassium lipids (amino acids peptides and proteins) |
| Zdroj: | The Journal of Membrane Biology. 63:191-198 |
| ISSN: | 1432-1424 0022-2631 |
| DOI: | 10.1007/bf01870980 |
| Popis: | We demonstrate that cholesterol can exchange from sonicated lipid vesicles to a perfused squid axon membrane and that vesicles with varying cholesterol/phospholipid (C/P) mole ratios can be used to achieve either net loading or net depletion of axon membrane cholesterol. Two types of evidence were obtained which show that net loading or depletion of cholesterol was achieved: (i) changes in the cholesterol/phospholipid (C/P) mole ratios of axons, and (ii) visualization of cholesterol depleted from the preparation by cholesterol-free vesicles by thin-layer chromatography. The C/P mole ratios indicate that cholesterol levels in the preparation were increased or decreased by 30-40%. Increasing or decreasing membrane cholesterol levels were ineffective in altering the Na+ or K+ occurrents in voltage-clamped axons. In addition, we determined that cholesterol "flip-flop" across the axonal membrane occurred with a t 1/2 of 7.3 to 15.3 min. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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