Haemolysis caused by alterations of α- and β-spectrin after 10 to 35 min of severe exercise

The pathophysiology of exercise related haemolysis is not thoroughly understood. We investigated whether exercise related haemolysis (1) is associated with alterations of red blood cell (RBC) membrane proteins similar to those found in inherited anaemic diseases, (2) can be induced with a non-running exercise mode, (3) is related to exercise intensity, and (4) coincides with indicators of oxidative stress. In ten triathletes [median (P25/P75-percentiles) age: 28.0 (26.3/ 28.5) years, height: 1.84 (1.78/1.87) in, body mass: 78.5 (74.8/80.8) kg, maximal oxygen uptake: 60.0 (57.3/ 64.8) ml kg(-1) min(-1)], haptoglobin, alpha- and beta-spectrin bands, malondialdehyde (MDA) and H2O2-Induced chemiluminescence (H2O2-Chem) were determined immediately pre- and post-both, a 35 min low intensity and a high intensity cycling exercise [240 (218/253) vs 290 (270/300) W, P < 0.05) requiring similar amounts of metabolic energy [28.3 (25.9/29.9) vs 24.9 (18.4/30.5) U kg(-1) P > 0.05]. At high exercise intensity haptoglobin [1.10 (0.81/2.53) vs 1.01 (0.75/2.00) g l(-1)] decreased (P < 0.05) whilst MDA [2.80 (2.65/3.20) vs 3.13 (2.78/ 3.31) nmol ml(-1)] and H2O2-Chem [29.70 (22.55/37.10) vs 37.25 (35.20152.63) rel. U min] increased (P < 0.05), coinciding with the disappearance of the spectrin bands in six out of ten gels. No corresponding changes were found at low intensity exercise. Ten to 35 min of non-running exercise in a regularly used intensity domain causes intra-vascular haemolysis associated with altera-tions in the RBC membrane proteins similar to those found after in vitro oxidative stress and in inherited anaemic diseases like Sphaerocytosis and Fanconi's anaemia.