Phosphatidylserine enhancement of [3H]gamma-aminobutyric acid uptake by rat whole brain synaptosomes.
[3H]gamma-Aminobutyric acid ([3H]GABA) binding to purified lipids was examined in an organic solvent-aqueous partition system. In addition, the [3H]GABA binding capacity in the partition system was compared with the capacity of lipids to alter sodium-dependent [3H]GABA uptake into synaptosomes isolated from rat whole brains. [3H]GABA was found to bind to all of the lipids studied in the organic solvent-aqueous partition system [phosphatidic acid (PA), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), gangliosides, and sulfatide], although PS exhibited the greatest binding capacity. [3H]GABA uptake into synaptosomes was enhanced by PS (48.0%) but was not altered by any other lipid. PS enhancement of [3H]GABA uptake required the presence of sodium and was blocked by nipecotic acid (10 microM). These results suggest that PS may play a role in the sodium-dependent GABA reuptake process in the presynaptic nerve end.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D007700:Kinetics; D008081:Liposomes; D008297:Male; D010718:Phosphatidylserines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D008081:Liposomes; D010718:Phosphatidylserines; D005680:gamma-Aminobutyric Acid; D002118:Calcium