Hemicholinium-3

Hemicholinium-3 (HC3), also known as hemicholine, is a drug which blocks the reuptake of choline by the high-affinity choline transporter (ChT; encoded in humans by the gene SLC5A7) at the presynapse. The reuptake of choline is the rate-limiting step in the synthesis of acetylcholine; hence, hemicholinium-3 decreases the synthesis of acetylcholine. It is therefore classified as an indirect acetylcholine antagonist.^[1]

Hemicholinium-3

Clinical data
Other names	2-[4-[4-(2-hydroxy-4,4-dimethylmorpholin-4-ium-2-yl)phenyl]phenyl]-4,4-dimethylmorpholin-4-ium-2-ol
ATC code	None
Identifiers
IUPAC name (2S,2S)-2,2'-biphenyl-4,4'-diylbis(2-hydroxy-4,4-dimethylmorpholin-4-ium)
CAS Number	312-45-8 Y
PubChem CID	9399
IUPHAR/BPS	4493
ChemSpider	9029 Y
UNII	65NY3I7ZD0
ChEMBL	ChEMBL268697 N
CompTox Dashboard (EPA)	DTXSID80883358
ECHA InfoCard	100.005.663
Chemical and physical data
Formula	C24H34N2O42+
Molar mass	414.546 g·mol−1
3D model (JSmol)	Interactive image
SMILES [Br-].[Br-].OC1(OCC[N+](C)(C)C1)c2ccc(cc2)c3ccc(cc3)C4(O)OCC[N+](C)(C)C4
InChI InChI=1S/C24H34N2O4.2BrH/c1-25(2)13-15-29-23(27,17-25)21-9-5-19(6-10-21)20-7-11-22(12-8-20)24(28)18-26(3,4)14-16-30-24;;/h5-12,27-28H,13-18H2,1-4H3;2*1H/q+2;;/p-2 Y Key:OPYKHUMNFAMIBL-UHFFFAOYSA-L Y
NY (what is this?)  (verify)

Acetylcholine is synthesized from choline and a donated acetyl group from acetyl-CoA, by the action of choline acetyltransferase (ChAT). Thus, decreasing the amount of choline available to a neuron will decrease the amount of acetylcholine produced. Neurons affected by hemicholinium-3 must rely on the transport of choline from the soma (cell body), rather than relying on reuptake of choline from the synaptic cleft.

Toxicity

Hemicholinium-3 is highly toxic because it interferes with cholinergic neurotransmission. The LD50 of hemicholinium-3 for mice is about 35 μg.^[2]

See also

• Triethylcholine
• Vesamicol

References

1. Carlson NR (2007). Physiology of Behavior (9th ed.). Boston: Pearson Education, Inc. p. 117. ISBN 978-0-205-46724-2.
2. Freeman JJ, Kosh JW, Parrish JS (October 1982). "Peripheral toxicity of hemicholinium-3 in mice". British Journal of Pharmacology. 77 (2): 239–44. doi:10.1111/j.1476-5381.1982.tb09291.x. PMC 2044599. PMID 7139185.