John Newport Langley and drug receptor theory

With the isolation of receptor proteins from cell membranes in the 1970s and the subsequent definition of receptor genes receptor theory became fact but a hundred years ago there was much controversy about the site and nature of drug action. In 1905 John Newport Langley, professor of physiology in Cambridge, described his concept of "receptive substances" as mediators of drug action in a paper in the Journal of Physiology that can be seen as the foundation of drug receptor theory ( Andreas-Holger Maehle. Medical History 2004 ; 48 : 153 -74).

In animal experiments in the 1870s Langley had shown that jaborandi, a plant extract containing pilocarpine, slowed the heart, the effect was reversed by atropine, and both effects were independent of vagus nerve function. Similarly pilocarpine stimulated the...