The modification of human erythrocyte membrane structure by membrane stabilizers: an electron spin resonance study.
Membrane structure in intact human erythrocytes was analyzed by electron-spin-resonance (ESR) spectroscopy. The spin probes 5-doxyl stearate and 5-doxyl stearate methyl ester revealed thermally-induced structural transitions in the membrane at 37 degree C and 15 degree C. The addition of propranolol, diazepam, chlorpromazine, or Pluronic F68 all caused a decrease in the temperature of the upper transition, but did not markedly alter the temperature of the lower transition. In addition, diazepam caused a significant decrease in the ordering or packing of the membrane-lipid acyl chains. It is proposed here that the protection from hypotonic hemolysis that has been reported in the presence of these drugs is mediated by a structural rearrangement in the erythrocyte membrane involving a change in protein-lipid interactions.
D002746:Chlorpromazine / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology*; D006461:Hemolysis; D006801:Humans; D011108:Polymers / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013696:Temperature
D011108:Polymers; C024617:polyol; D011433:Propranolol; D003975:Diazepam; D002746:Chlorpromazine