Na(+)-dependent high-affinity uptake of choline into cultured fibroblasts.
The acetylcholine precursor choline is transported into cholinergic neurons by a high-affinity, sodium-dependent mechanism that is selectively localized to the cholinergic nerve terminal. In addition, a low-affinity, sodium-independent choline uptake system is present in cholinergic and non-cholinergic cells which deliver choline for cell membrane anabolism. Here, we show that uptake of [3H]choline into cultured fibroblast cell lines exhibits high affinity (Km < or = 10 microM), is sodium-dependent, and is blocked by hemicholinium, a classical inhibitor of neuronal high-affinity choline uptake. Our data indicate that sodium-dependent high-affinity choline transport systems are also present in non-cholinergic cells.
Schloss
P
P
Abteilung Neurochemie, Max-Planck-Institut für Hirnforschung, Frankfurt, Germany.
Mayser
W
W
Niehuis
A
A
Betz
H
H
D001693:Biological Transport, Active / Q000187:drug effects; D002460:Cell Line; D002794:Choline / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007668:Kidney; D007700:Kinetics; D012964:Sodium / Q000494:pharmacology*; D013997:Time Factors; D014316:Tritium
D014316:Tritium; D012964:Sodium; D002794:Choline