Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans

Abstract

Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

Rapid cortisol signaling in response to acute stress involves changes in plasma membrane order in rainbow trout liver

“…The plasma membrane is highly sensitive to the surrounding physical and chemical environment, leading to the proposal that the plasma membrane is the primary detector of stress stimuli and activator of the cellular stress response (48). Subsequently, recent studies suggest that the plasma membrane is central in mediating the cellular stress response and aiding in cellular tolerance to a variety of stressors, including osmotic (34), temperature (44), and oxidative stress (3). This study provides additional evidence for the membrane-sensing model, as we show for the first time that a physical stressor rapidly fluidizes plasma membranes.…”

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“…[4,5,7] In the studies of Zuk et al, it was also found out that an increase in the erythrocyte elastic modulus worsens the ability of a cell to bind oxygen and transport it through capillaries. [1,7,15] It is known that blood cells suspended in plasma or physiological salt solution (erythrocytes, platelets and leukocytes) carry a negative charge at their physiological pH, which ensures their normal functioning. [10,16] In our studies, the value of the surface potential of the erythrocyte membrane on the 30 th day of adaptation in the blood of chickens in group 2 was 51% higher than the values in the control group.…”

“…It gives an objective assessment of the physiological state of the organism and predicts the development of an adaptation process in changing environmental conditions. [1][2][3][4] The parameters of the erythrocyte geometry characterize the properties of red cells to deform under external impact and to change the viscous properties of blood, which largely determines the quality of capillary blood flow and indicates a certain change in the rheological properties of the blood. [1,[5][6][7] In this regard, the study of structural and metabolic status of red blood cells of chickens when adapting to production factors is not only of scientific but also of practical interest.…”

Age-related changes in erythrocyte membrane sulfhydryl groups and β-D-glucuronidase activity

“…Increased oxidative stress has been linked to a shortening of life span [2]. Several studies report alterations in the erythrocyte membrane during human aging [4,5].…”