gms | German Medical Science

Objective: People have used extremely hot air for ages for hygiene, relaxation, for social or also medicinal goals. Extremely high temperature which affects human organism like sauna, is one of the oldest of such procedures [1]. As a result of sauna, the sympathetic nervous system and hormonal axis hypothalamus-pituitary-adrenal are activated, in order to keep thermal balance of the organism. Therefore, thermal impulse is connected i.a. with increased concentration of noradrenalin [2], [3]. The concentration of adrenaline does not change or it increases. Alterations result from different conditions of cooling [4]. After sauna the increased secretion of adrenocorticotropic hormone (ACTH) is also noted [2], [3] and after sauna procedures with cooling by immersion in ice-cold water, secretion of cortisol increased, too [4]. After sauna bathing in healthy subjects’ blood plasma of both sexes the concentration of beta-endorphins and prolactin is also elevated [2].

The final effect of the hormonal changes is water retention, “fight-or-flight” response of the organism, increase of dermal blood flow, heart rate and sweating. There is reduced perception of pain, elated mood and alertness [2], [3]. Reduction of plasma volume and loss of sodium during sweating activates renin-angiotensin-aldosterone system [4]. The concentration of arginine, vasopressin and natriuretic hormone during sauna procedures increases significantly. In men the concentration of testosterone is not changed [5].

The aim of the study was to indicate the effect of dry sauna on the activity of antioxidant enzymes (PON – paraoxonase, CAT – catalase, SOD – superoxide dismutase, GPx – glutathione peroxidase) and also on the concentration of lipid peroxidation product (TBARS – thiobarbituric acid reactive substances) in blood of healthy men.

Material/Methods: Subjects (n=7) performed single dry sauna procedure (three entries into sauna, each 10 min), in temperature of 90°C and relative air humidity of 10%. After each exit from sauna, men cooled their whole body surface due to cold shower. The blood samples were taken from cubital vein before the entry to sauna, 15 and 60 min after the exit. The activity of CAT, SOD, GPx was expressed in U/g of Hb. The activity of paraoxonase was expressed in IU/l of serum.

The main product of lipid peroxidation reacting upon thiobarbituric acid (TBA) is malondialdehyde (MDA) so for simplification the level of TBARS in erythrocytes was expressed as nmol of MDA/g of Hb and in the blood plasma as nmol of MDA/ml of plasma.

The obtained results were statistically analyzed by using ANOVA test. The changes of the level p<0.05 were accepted as statistically significant.

Results: Statistically significant increase of the activity of SOD was revealed 15 and 60 min after exit from sauna in comparison to the SOD activity before entry to sauna (p<0.05). In the paper increasing tendency of activity of PON, GPx and CAT and the concentration of TBARS (in blood plasma) both 15 and 60 min after exit from sauna was found as compared to activity of PON, GPx and CAT and the concentration of TBARS (in blood plasma) before entry to sauna (control).

Statistically significant very high positive correlation (r=0.828; p<0.05) was noticed between the activity of CAT and SOD before entry to sauna.

Conclusion: Single dry sauna procedure increases the generation of free radicals thus it disturbs oxidant-antioxidant balance in the organism.