The structural specificity of choline transport into cholinergic nerve terminals.
The accumulation of choline, homocholine, and 4-hydroxybutyltrimethylammonium by rat brain synaptosomes was measured; the choline uptake mechanism transported homocholine but not hydroxybutyltrimethylammonium, which, in addition, did not block choline accumulation. In cats' superior cervical ganglia, preganglionic nerve stimulation increased the accumulation of homocholine, but not that of hydroxybutyltrimethylammonium. It is concluded that the substrate specificity of the choline transport mechanism is  such that increasing the N--O atom distance by one methylene group retains affinity, but increasing this distance by two methylene groups does not.
D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000031:analogs & derivatives / Q000378:metabolism*; D066298:In Vitro Techniques; D009411:Nerve Endings / Q000378:metabolism*; D010275:Parasympathetic Nervous System / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity; D013574:Synaptosomes / Q000378:metabolism
D002794:Choline