The TiPS lecture: functional aspects of the neuronal uptake of noradrenaline

For various amine transmitters (noradrenaline, dopamine, 5-HT) re-uptake into the releasing varicosity limits the transmitter's life span in the biophase. In the second TiPS Lecture, given at this year's FASEB meeting in Atlanta, Georgia, Ullrich Trendelenburg summarized the evidence relating to the function of the neuronal noradrenaline carrier (uptake1), why it is absolutely dependent on Na+ and Cl- and how it functions as a metabolizing system, hand in hand with intraneuronal monoamine oxidase and vesicular storage. This carrier clears noradrenaline from the extracellular space very efficiently. Hence, loading of incubated organs with exogenous substrates of uptake1 results in a very heterogeneous distribution of the amine. Moreover, under certain experimental and pathophysiological conditions the carrier is able to transport axoplasmic noradrenaline out of the varicosity, a 'release' mechanism operating, for instance, in cardiac ischaemia.