Receptors as Drug Targets

Receptors are used by living cells for perceiving stimuli and for transmitting the message, to the cellular machinery, leading to specific responses Paul Ehrlich gave the idea of using receptors as the binding sites for therapeutic agents (drugs), in order to block or to stimulate the response further. It involves the use of antagonists to block the signal and that of agonists to turn on the signal usually generated due to a receptor. One of the earliest examples of such receptors included the discovery of two types of adrenotropic receptors, whose characterization led to the development of several drugs which work as beta-blockers and beta-agonists. For instance, benzodiazepine enhances the effect of GABA (g-aminobutyric acid) and chloride (CI-) flux, using benzodiazepine receptor. Similarly, certain monoclonal antibodies block the receptors of growth or differentiation that are found on the surface of tumour cells. Several other receptor targets have been hypothetically associated with certain diseases. Following are some examples (i) lectin receptor is associated with obesity; (ii) low density lipoprotein (LDL) receptor is associated with atherosclerosis; (iii) complement receptors are associated with inflammation; and (iv) interelukiin-4 (IL-4) is associated with allergic disease