Cyclic nucleotides are intimately involved in the consequences of either stimulation or blockade of receptors; therefore, an understanding of the biochemistry of cyclic nucleotides ought to be important for pharmacologists. Pharmacology is a science that among other things investigates chemical compounds that affect the physiology of cells, tissues and organs. Frequently pharmacologists account for the effect of low concentrations of a drug upon a tissue by invoking the presence of a receptor upon the surface of the cell. Traditional pharmacologists excelled at identifying and classifying the...