Red but not Dead: Not a Hapless Sac of Hemoglobin

Abstract

The purpose of this presentation was to demonstrate that the red blood cell is not a hapless sac of hemoglobin and that much research is still needed for better understanding of its complexities. After a brief historical introduction the following subjects are presented: 1). Phosphofructokinase is the rate limiting step in the anaerobic glycolytic pathway. Ribose-5-phosphate, a metabolite of the oxidative pentose phosphate pathway is essential for the generation of phosphoribosylpyrophosphate which in turn is needed for the synthesis of adenosine monophosphate from adenine by the action of adenine phosphoribosyl transferase. 2). There are at least 17 blood group systems with more than 400 epitopes expressed on the red cell membrane. The Rh null and the McLeod phenotypes associated with abnormally shaped red cells and hemolytic anemia are briefly described as is the present understanding of the nature of the Rh complex. 3). The structure of the cytoskeleton and the composition and behavior of the lipid bilayer are presented with some discussion of the MN and Ss sialoglycoproteins and the Leach phenotype. 4). Touched upon is the role of phosphoinositides with some emphasis on recent discoveries relating to the glycophosphoinositide protein anchor. 5). The intricacies of the many faceted transport mechanisms are introduced. Briefly mentioned are the mechanisms activated when regulatory volume adjustments occur in fine tuning red cell volume after exposure respectively to hypotonic or hypertonic stress. Sufficient evidence is presented to convince that a cell doesn't have to have a nucleus to be respected even though it is just a corpuscle.