Effect of drugs on the uptake and release of 3H-norepinephrine in the rat heart

Abstract

FOLLOWING the administration of a wide variety of drugs such as psychoactive agents (reserpine, chlorpromazine, imipramine), sympathomimetic amines (tyramine, amphetamine), cocaine, adrenergic blocking agents (phenoxybenzamine), and hypotensive drugs (guanethidine) a lower concentration of injected 3H-noradrenaline was found in the heart, spleen and adrenal glands1-3. Most of these drugs also increase the rate of metabolism of 3H-noradrenaline in the whole mouse presumably by preventing the protective binding of the hormone and exposing it to enzymatic attack4,5. Although these drugs have many actions, they could produce a common-end result by different mechanisms. They might lower the tissue levels of 3H-noradrenaline by blocking the entry of the circulating catecholamine into the storage site, preventing the binding or causing the release of the bound 3H-noradrenaline or by a combination of these. © 1962 Nature Publishing Group.