Determination of erythrocyte membrane deformability after exercise by means of the haemolytic action of mercury ions

Abstract

Twenty-two healthy young male volunteers, between 15 and 19 years of age, took part in this study. They were subjected to a series of exercises on a veloergometer loaded at two submaximal levels of 1.5 W/kg and 2.0 W/kg, both at 60 steps/min for 4 min, and one maximal level, which commenced at 3.0 W/kg at 70 steps/min and increased every minute by 0.15 W/kg. The exercise was terminated when the frequency of the steps could not be regularly maintained. Blood samples were taken before and after exercise. Erythrocyte membrane deformability was studied by means of cation osmotic haemolysis (Mojzis and Nicak 1993; Nicak and Bohus 1993). The haemolytic action of HgCl2 (0.15 mmol/l) was studied in relation to the ionic strength of NaCl in the incubating medium. Ionic strength ranged from 0.0 to 154.0 mmol/l NaCl, the isotonicity being corrected with glucose. The haemolysis of the samples was compared with a control sample incubated in distilled water (100% haemolysis), the degree of haemolysis in the tests being measured spectrophotometrically at 540 nm. The significance of differences was evaluated using Student's t-test. On the basis of ionic strength and the amount of glucose present, two high levels of haemolysis were observed, the first at low concentrations of NaCl/high concentrations of glucose, and the second at high concentrations of NaCl/low concentrations of glucose. The course of the haemolysis curves before and after exercise was similar, showing a non-significant decrease after exercise, with the exception of one individual where the difference was significant.