Chapter 101. Hemolytic Anemias and Anemia Due to Acute Blood Loss (Part 3)

Figure 101-1 RBC metabolism. The Embden-Meyerhof pathway (glycolysis) generates ATP for energy and membrane maintenance. The generation of NADPH maintains hemoglobin in a reduced state. The hexose monophosphate shunt generates NADPH that is used to reduce glutathione, which protects the red cell against oxidant stress. Regulation of 2,3-bisphosphoglycerate levels is a critical determinant of oxygen affinity of hemoglobin. Enzyme deficiency states in order of prevalence: glucose-6-phosphate dehydrogenase (G6PD) pyruvate kinase glucose-6-phosphate isomerase rare deficiencies of other enzymes in the pathway. The more common enzyme deficiencies are encircled. . | Chapter 101. Hemolytic Anemias and Anemia Due to Acute Blood Loss Part 3 Figure 101-1 Embden- Meye r h -of pathway Hex-ose monophosphate sh uni Glutaihione GSH reductase GSSG glucose j ATP ADP_ glticpse-G-phosphale glucose priosphaï -S-phosphogl uconate lruciosa-6-phosphâtfl - ATP N nr -a pnosphorTuelakuiase ADP n- frnciwe-1 -diptw 5ph le aktelaw HbF02 HbFaS glyceraldehyde Y NAt glycaraldehytie 3-phOsphate NAOH phOSpl lyœr Wh hOQl ADP -x priMphogtyi ATP kinase 3-pbosphogiycerate . J 3- phosphoglyOersle mdtAM -phosphoglycerala ffll .3-bi5phosphogiyceratë 2 3 t spiiospfK giyctNat i phosphate sc enptaw phg5f hoenolpyiuvate ADP J ---------------7 C pyruvate kint ATP ---------------------- pyruvâle NADH lactate NAD jBh rdrD9er sa lactate Sd Jfc i F u l AS. K fp r DL. fcraunw ld E. H ui r SL. Lornjo DLu J maioA JL. LfMCtlzo Ji Mhfjrfra i d fa fiA4r 17th ErÎitfùfi http -. fTi. di -in ric rt . Copyright 3 Th Compim . Ihc 11 rigMi i pv d- RBC metabolism. The Embden-Meyerhof pathway glycolysis generates ATP for energy and membrane maintenance. The generation of NADPH maintains hemoglobin in a reduced state. The hexose monophosphate shunt generates NADPH that is used to reduce glutathione which protects the red cell against oxidant stress. Regulation of 2 3-bisphosphoglycerate levels is a critical determinant of oxygen affinity of hemoglobin. Enzyme deficiency states in order of prevalence glucose-6-phosphate dehydrogenase G6PD pyruvate kinase glucose-6-phosphate isomerase rare deficiencies of other enzymes in the pathway. The more common enzyme deficiencies are encircled. Thus the essential pathophysiologic process common to all HAs is an increased red cell turnover. The gold standard for proving that the life span of red cells is reduced compared to the normal value of about 120 days is a red cell survival study which can be carried out by labeling the red cells with 51Cr and measuring residual radioactivity over several days or weeks .