Effect of benzyl alcohol on phospholipid transverse mobility in human erythrocyte membrane.
The effect of benzyl alcohol on the transverse mobility and repartition of phospholipids in the human erythrocyte membrane was investigated using electron spin resonance and morphological modification of red blood cells. Transmembrane internalization rates and equilibrium distribution in red blood cells of short-chain spin-labeled phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine were strongly modified by treatment with 10-70 mM benzyl alcohol. A dual effect was observed: (a) at 4 degrees C and 37 degrees C there was an N-ethylmaleimide-sensitive, long lasting and fully reversible increase in the spin-labeled phosphatidylserine and phosphatidylethanolamine internalization rate; (b) at 37 degrees C, an enhancement of N-ethylmaleimide-insensitive fluxes of all the labeled phospholipids through the membrane occurred. Both effects were dose-dependent. Erythrocytes submitted to benzyl alcohol incubation also showed dose-dependent shape changes: an immediate one from discocytes to echinocytes, followed by a slower N-ethylmaleimide- and ATP-dependent change to stomatocytes. Moreover, benzyl alcohol treatment was shown to lead to enhanced hydrolysis of intracellular ATP. All the effects of benzyl alcohol can be described as an accumulation of labeled phosphatidylethanolamine (and labeled phosphatidylcholine at 37 degrees C) in the inner leaflet. This can be interpreted as a perturbation of the erythrocyte membrane, leading to an energy-consuming specific increase in aminophospholipid translocase activity, in addition to a slow and passive bidirectional flux of all phospholipids at 37 degrees C.
Bassé
F
F
URA CNRS 530, Département Biologie-Santé, Montpellier, France.
Sainte-Marie
J
J
Maurin
L
L
Bienvenüe
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D019905:Benzyl Alcohol; D001592:Benzyl Alcohols / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D003958:Diamide / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004907:Erythrocyte Deformability / Q000187:drug effects; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids / Q000378:metabolism*
D001592:Benzyl Alcohols; D002352:Carrier Proteins; D008565:Membrane Proteins; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D003958:Diamide; D000001:Calcimycin; D000255:Adenosine Triphosphate; D019905:Benzyl Alcohol; D005033:Ethylmaleimide