Peptides and peptidomimetics
A large number of endogenous peptides have been isolated and characterized (Table 15.1). These peptides are involved in a wide range of important physiological processes both centrally and peripherally. Drug intervention with the formation, breakdown or receptor interaction of peptides might provide therapeutic opportunities. The most wellknown drug that interacts with peptide receptors is morphine. It was isolated from opium in 1803. However, whereas its analgesic efficacy and other CNS effects were discovered already in the nineteenth century, the fact that morphine interacts with receptors for opiate peptides was verified only relatively recently. Currently, numerous drug discovery efforts are focussed on processes involving peptides and intense research and development efforts during the past 30 years have provided important peptide interacting drugs such as captopril and losartan.