Pharmacological Control of the Synthesis and Metabolism of Cyclic Nucleotides

This chapter discusses the pharmacological control of the synthesis and metabolism of cyclic nucleotides. A cyclic nucleotide mediates the epinephrine-induced activation of liver phosphorylase. Adenosine 3'3'-monophosphate (cyclic AMP) and other cyclic nucleotides have been demonstrated not only to mediate the effects of most hormones and neurotransmitters but also to be involved in scores of biochemical and physiological events. The evidence that cyclic nucleotides influence the function of normal cells suggests that any abnormal alteration in the concentration of these compounds may be responsible for abnormal cell function that is, a diseased state. Indeed, several lines of investigation indicate that cyclic nucleotides may be involved in a variety of clinical conditions ranging from cancer to cardiovascular disease to mental illness. Cyclic AMP and the enzymes responsible for its biosynthesis and degradation are present in all tissues at all stages of their development. However, the rate at which these enzymes develop varies with the tissue and species. Moreover, the rate at which the hormone-sensitive adenylate cyclase system develops does not necessarily coincide with the development of the basal or fluoride-stimulatable enzyme.