Arylalkylamines in the adrenal medulla.

The trace amines p-tyramine, m-tyramine, tryptamine, and phenylethylamine have been determined in the bovine adrenal medulla and the rat adrenal gland by the mass spectrometric integrated ion current technique, using the corresponding deuterated amines as internal standards. In the bovine adrenal medulla, these amines were present at levels ranging from 21.7 ng/g for tryptamine to 37.3 ng/g for phenylethylamine, while in the rat adrenal, they occurred in amounts ranging from 5.2 ng/g for m-tyramine to 11.4 ng/g for tryptamine. In the rat, intraperitoneal administration of pargyline (100 mg/kg) increased the adrenal levels of each of the trace amines. Adrenaline, noradrenaline, and p-tyramine were significantly depleted by reserpine (3 or 10 mg/kg), but the level of m-tyramine was unaffected. It is suggested that the mode of uptake of the tyramine isomers into the adrenal medullary granules may depend on the position of the bydroxyl group relative to the side chain on the aromatic nucleus.