Evidence that erythrocytes are highly susceptible to exercise oxidative stress: FT-IR spectrometric studies at the molecular level.
We tested the hypothesis that usual exercise oxidative stress strongly affects erythrocytes viability. A 120-min physical exercise with progressive intensity was used as a model of oxidative stress. FT-IR spectrometry was used to determine structural changes in erythrocyte contents (phospholipids, proteins, lactate, and glucose) from blood samples taken every 20 min. Carbonyl formation from amino acid residues (P = 0.03) and hemoglobin unfolding (P = 0.01) could be identified as main protein denaturation markers during oxidative stress. Higher unsaturation level (P = 0.001) in phospholipids fatty acyl chains were also observed while VO(2) increased (P < 0.05). The increase in lactacidosis affected primarily hemoglobin unfolding (P = 0.02). Finally, two distinct cellular events occurred during oxidative stress: 1 - phospholipids peroxidation correlated to VO(2), but lactacidosis and hemoconcentration remained secondary factors; 2 - hemoglobin denaturation was mainly observed through unfolding and carbonylation, and lactacidosis and hemoconcentration were important contributing factors.
Petibois
Cyril
C
CNRS UMR 5084, CNAB, Groupe de Chimie Bio-Organique, Bordeaux, France. cyril.petibois@u-bordeaux2.fr
Déléris
Gérard
G
D000140:Acidosis, Lactic / Q000209:etiology; D004912:Erythrocytes / Q000378:metabolism*; D015444:Exercise; D005947:Glucose / Q000032:analysis; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000032:analysis; D018384:Oxidative Stress; D010743:Phospholipids / Q000032:analysis; D010807:Physical Endurance; D017510:Protein Folding; D011506:Proteins / Q000032:analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
D006454:Hemoglobins; D010743:Phospholipids; D011506:Proteins; D019344:Lactic Acid; D005947:Glucose