In the span of a few short years the therapeutic management of essential hypertension has been transformed from one of gross empiricism to that of a stable, rational approach based on established pharmacological principles. This success has required a close liaison among the disciplines of chemistry, of pharmacology, and of the clinic, for the niceties and fine nuances governing the relationship between chemical structure and type of biological activity of a compound are all too elusive for charting a reliable course through unfamiliar synthetic molecular configurations. Although autonomic...