Release and depletion of the transmitter in adrenergic terminals produced by nerve impulses after the inhibition of noradrenaline synthesis or reabsorption

Subcellular distribution of [3H]-epsilon-aminocaproic acid and its effects on amine storage mechanisms

ε-Aminocaproic acid (EACA) is an amino-acid reported to cause almost complete depletion of cardiac noradrenaline stores. The present report indicates that this compound can be found in both the particulate and supernatant fractions derived from heart homogenates. The [3H]EACA in the supernatant probably represents a mixture of intra- and extraneuronally located drug. Protriptyline pretreatment decreases the uptake of [3H]EACA suggesting that the amino-acid probably utilizes the amine membrane transport system, EACA, like reserpine, can both impair the retention of exogenously administered amines by adrenergic storage particles and cause the release of amines previously stored in such particles.