Hemicholinium-3-resistant choline uptake system linked to acetylcholine synthesis in the rat hippocampus.
Extracellular choline-dependency of acetylcholine (ACh) synthesis was examined in rat hippocampal slices. In the presence of hemicholinium-3 (HC-3, 5 microM), extracellular choline-dependent ACh synthesis appeared to consist of two different components. The first component (saturated at up to 50 microM choline) was dependent on the HC-3-resistant choline uptake system having a low capacity for choline in comparison with the high-affinity choline uptake system (HACU). The second component, observed in the presence of more than 50 microM choline, was considered due to competitive inhibition of HACU by HC-3. HACU-dependent ACh synthesis seemed to be saturated in the presence of up to 2 microM choline. These results indicate that both the HACU and HC-3-resistant choline uptake systems are linked to ACh synthesis in the hippocampus.
Suzuki
T
T
Department of Pharmacology, Kyoritsu College of Pharmacy, Tokyo, Japan.
Kashima
Y
Y
Kawashima
K
K
D000109:Acetylcholine / Q000096:biosynthesis*; D000818:Animals; D002794:Choline / Q000378:metabolism*; D005260:Female; D006426:Hemicholinium 3 / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D006426:Hemicholinium 3; D002794:Choline; D000109:Acetylcholine