Interference of inhibitors of dopamine-beta-hydroxylase with uptake of monoamines by chromaffin granular membranes.

Disulfiram and bis-(4-methyl-1-homopiperazinylthiocarbonyl)-disulphide (FLA 63) markedly inhibited the Mg2+/ATP-dependent uptake of various monoamines, e.g. dopamine (DA), by isolated membranes of bovine adrenal chromaffin granules. Both compounds affected DA-beta-hydroxylase (DBH) activity more markedly than the uptake of DA. Other inhibitors of DBH, e.g. fusaric acid and diethyldithiocarbaminate (DDC), did not interfere with DA uptake. Disulfiram and FLA 63, in contrast to fusaric acid and DDC, also caused a partial inhibition of Mg2+-dependent ATPase. It is concluded that the inhibition of monoamine uptake by disulfiram and FLA 63 is not related to their effect on DBH.