Activity of selected enzymes in erythrocytes and level of plasma antioxidants in response to single whole-body cryostimulation in humans.

The influence of extremely low temperatures on the human body and physiological reactions is not fully understood. The aim of this research was to estimate the influence of a single exposure to cryogenic temperature (-130 degrees C), without subsequent kinesiotherapy, on the activity of the most crucial antioxidant enzymes in erythrocytes: superoxide dismutase (SOD), catalase (CAT), glutathione reductase (R-GSSG), glutathione peroxidase (GPx) and glutathione transferase (T-GSH). In the plasma, the concentrations of glutathione, uric acid, albumins and extra-erythrocyte haemoglobin as components of the non-enzymatic antioxidant system were evaluated. The subjects were 10 healthy young men. Blood was sampled in the morning on the day of cryostimulation, 30 min after cryostimulation and the next morning. The enzymatic response of the antioxidant defence to the influence of the extremely low temperature resulted in an immediate, significant, increase in GPx and R-GSSG activities, but a decrease in CAT and T-GSH activities. We observed an increase in the concentrations of all the examined non-enzymatic antioxidants, especially extra-erythrocyte haemoglobin and uric acid, which had both increased further the day after cryostimulation. The results indicate that a single stimulation with cryogenic temperatures results in oxidative stress in a healthy body, but that the level of stress is not very high. It seems that in this case the most significant role in the antioxidant mechanisms is played by peroxidase.