role of different additives in blood bags

[drraj_j]

what is the role of glucose in blood bag as preservative.some book says it increases viability of RBCs after transfusion and some says it provides energy and some says it increases 2,3 DPG but if to choose one of them what will be the right answer

[dheathco]

Well in a way they are all correct ! Glucose is provided to support red cell metabolism and provide energy to the red cell. Red cells metabolise by anerobic glycoysis which uses glucose as its substrate and produces ATP. ATP is used by the cell to maintain its membrane pumps and keep haemoglobin reduced, without ATP the cell will swell and burst. Thus to keep red cells in good condition for transfusion (and to enhance their viability in the recipient) we need to keep them metabolically alive. A byproduct of glycolysis is 2,3-BPG (previously known as 2,3-DPG) which is the most abundant phosphated molecule in the red cell and plays a major part in the affinity of haemoglobin for oxygen.

We have known for many years that if you need a marker for the 'health' of stored red cells that levels of 2,3-BPG correlate well with 'healthy' red cells and that the longer you keep levels high the better. Unfortunately you can't just add more glucose to get more ATP because glycolysis is capped at how fast it can proceed. In the development of storage solutions the CP2D or 'double dextrose' formulas did increase the length of time that 2,3-BPG levels could be kept elevated for but levels of glucose higher than this don't increase it any further. One of the strategies to keep 2,3-BPG levels higher for longer has been to add addenine which can enter the glycolytic pathway halfway down and stimulate additional 2,3-BPG production.

Sorry for the complex reply !

[Malcolm Needs ☆]

Complex maybe, but excellent!