Tissue specificity of purine metabolism

Abstract

In Chapter 2 we saw the possible ways in which the basic mechanisms of synthesis and salvage interact in order to sustain the cellular nucleotide levels of ATP, GTP, DNA and RNA. In this chapter we will explore briefly just how much individual variation there may be depending on the function of a particular tissue or organ and its rate of turnover. This in turn involves changes in controls — metabolic switches — which determine the flow of metabolites to a particular nucleotide pool. In most tissues, for instance, DNA is relatively stable, except for those with a high rate of turnover such as intestine, skin and bone-marrow. In view of the tissue specific regulatory functions of adenosine it is becoming increasingly possible that such tissue specificity may have some evolutionary significance.