URIC-ACID AND GLUTATHIONE LEVELS DURING SHORT-TERM WHOLE-BODY COLD-EXPOSURE

Ten healthy subjects who swim regularly in ice-cold water during the w inter (winter swimming), were evaluated before and after this short-te rm whole body exposure. A drastic decrease in plasma uric acid concent ration was observed during and following the exposure to the cold stim ulus. We hypothesize that the uric acid decrease can be caused by its consumption after formation of oxygen radicals. In addition, the eryth rocytic level of oxidized glutathione and the ratio of oxidized glutat hione/total glutathione also increased following cold exposure, which supports this hypothesis. Furthermore, the baseline concentration of r educed glutathione was increased and the concentration of oxidized glu tathione was decreased in the erythrocytes of winter swimmers as compa red to those of nonwinter swimmers. This can be viewed as an adaptatio n to repeated oxidative stress, and is postulated as mechanism for bod y hardening. Hardening is the exposure to a natural, e.g., thermal sti mulus, resulting in an increased tolerance to stress, e.g., diseases. Exposure to repeated intensive short-term cold stimuli is often applie d in hydrotherapy, which is used in physical medicine for hardening.