The influence of exercise-induced oxidative stress on binding and degradation of 125I-insulin by the receptors on erythrocytes.
In the present work we investigated the influence of oxidative stress induced by strenuous exercise on the affinity of a specific insulin receptors on human erythrocytes. 13 male members of the national basketball staff performed a maximal treadmill exercise test. In the blood samples collected before and directly after the test acid-base equilibrium parameters, lactic acid concentrations, glucose and insulin serum levels as well as 125I-insulin binding and degradation by receptor on erythrocytes were measured. As markers of oxidative stress, plasma thiobarbituric acid-reactive substance levels (TBARS) and red blood cells glutathione content (GSH) were determined. After the exercise test TBARS levels increased significantly and GSH concentrations decreased indicating that oxidative stress occurred. Binding of 125I-insulin to the receptors on erythrocytes decreased significantly during the test, while there was only insignificant reduction in 125I-insulin degradation. Correlation analysis and multiple linear regression revealed that changes in insulin degradation by receptors on erythrocytes during exhaustive exercise are determined by oxidative stress, probably via oxidation of sulfhydryl groups of certain enzymes. The affinity of receptors for insulin seems to depend mainly on glucose concentrations.
Szcześniak
L
L
Chair of Physiology, Biochemistry and Hygiene, University School of Physical Education, Poznań, Poland.
Karolkiewicz
J
J
Deskur
E
E
Rychlewski
T
T
Konys
L
L
Stankiewicz
K
K
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002245:Carbon Dioxide / Q000032:analysis; D004912:Erythrocytes / Q000378:metabolism*; D005080:Exercise Test; D005978:Glutathione / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D007457:Iodine Radioisotopes; D016014:Linear Models; D008297:Male; D018384:Oxidative Stress; D010101:Oxygen Consumption; D011972:Receptor, Insulin / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D001786:Blood Glucose; D007328:Insulin; D007457:Iodine Radioisotopes; D017392:Thiobarbituric Acid Reactive Substances; D002245:Carbon Dioxide; D011972:Receptor, Insulin; D005978:Glutathione