Effects of Some Pharmacologically Active Amines on the Uptake of Arylalkylamines by Adrenal Medullary Granules

The effect of reserpine, chlorpromazine and related compounds on the uptake of catecholamines by the adrenal medullary granules from the cow has been studied in vitro. Both types of drugs were found to be competitive inhibitors of the adrenaline uptake by the granules. Thus they compete with adrenaline for the same groups in the uptake mechanism for catecholamines. Tryptamine was also found to accumulate in the granules but not by the same mechanism as used by the catecholamines and 5‐hydroxytryptamine, as Mg2+, ATP and reserpine did not have any influence on the uptake. The Km‐values for the uptake of adrenaline and 5‐hydroxytryptamine were 8 × 10‐4 and 1.1 × 10‐4, respectively.