ABSTRACT
Purine compounds such as adenosine 5′-triphosphate (ATP) and adenosine (Figure 6.1) play important roles in energetic metabolism, synthesis of nucleic acids and enzymatic regulation in living organisms. Nevertheless, the functions of these compounds are not restricted to intracellular actions but also to extracellular tasks. It is accepted that purines are stored by neurons and other cells together with other chemical messengers such as hormones and neurotransmitters. Stimulation of these cells evoke the release of purine compounds into the extracellular media, producing different effects in tissues due to their binding to specific purine receptors present in cell membranes. This chapter describes the actions of adenosine, ATP and other nucleotides in the eye structures. Possible implications in pathological processes and future developments are also indicated.
