Catecholamine transport by the organic cation transporter type 1(OCT1)

摘要

Liver and kidney extract adrenaline and noradrenaline from the circulation by a mechanism which does not seem to be one of the classical catecholamine transporters. The hypothesis that OCTl is involved- the organic cation transporter type 1 which exists in rat kidney and liver-was tested. Based on human embryonic kidney cells(293), we constructed a cell line which stably expresses OCTlr(293_OCTlr cells). Transfection with OCT1 resulted in a transport activity not only for prototypical Known substrates of OCT1 such as ~3H-1-methyl-4-phenylpyridinium and ~14C-tetraethylammonium but Also for the catecholamines ~3H-adrenaline, ~3H-noradrenaline(~3H-NA) and ~3H-dopamine(~3H-DA), the Indoleamine ~3H-5-hydroxytryptamine (~3H-5HT) as well as the indirect sympathomimetic ~14C-tyramine.