Sanne de Bruin

15 General Introduction and scope of the thesis Figure 2 Overview glucose and glutathione metabolism in RBCs During storage, glucose is catabolized to lactate to generate ATP. Consequently, the pH declines gradually throughout storage. The optimal pH of the rate limiting enzyme of the glycolysis, phosphofructokinase (PFK), is 8.1 41 . As RBCs are completely dependent on the glycolysis for their energy supply, this results in decreased ATP levels. Further- more, the glycolysis provides metabolites to the Luebering Rapoport shunt which are converted to 2,3-DPG. The 2,3-DPG levels are completely depleted within 2 weeks after storage 40 . 2,3-DPG is a metabolite which decreases the oxygen affinity of haemoglobin and thereby maximizes the oxygen release to the peripheral tissues. In the oxidative PPP, glucose is converted to ribose. In this process NADPH is produced, which is important to maintain reduced glutathione (GSH) levels. GSH detoxifies reac- 1