Selectivity of alpha 1 and alpha 2 adrenergic agonists and antagonists

The recent contributions in the selectivity of ligands acting at the adrenergic alpha-receptor toward pre- and post-synaptic receptors (i.e. alpha 1 and alpha 2-receptors) are reviewed. Furthermore, tissue differences and possible sub-classification of pre- and post-synaptic alpha-receptor types are discussed.