Aim: 

The high altitude environment can induce various cellular effects, depending on the absolute altitude and the duration of exposure. These effects could be mainly induced by a reduced capacity to scavenge the excessive ROS production (Grocott et al, Critical.Care 11:203, 2007), as well as the depression of immunological function.

Methods: 

In this study we tested the functional activity of peripheral blood lymphocytes isolated from seven climbers before and after a 21-day period of exposition to hypobaric hypoxia (over 5000 m). We analysed two interlinked intracellular patterns: (1) the intracellular Ca²⁺ homeostasis and (2) the enzymatic antioxidant response and mitochondrial integrity.

Results and Conclusion: 

Our data revealed that high altitude caused: (i) an increased intracellular Ca²⁺ concentration and a decreasedmitochondrial membrane potential, (ii) conversely the antioxidant enzymatic response was not affected. Overall, these results suggest that high altitude might cause an impairment in antioxidant adapted response, as indicated by both the decreased mitochondrial activity and the lack of increase of one of the major antioxidant enzyme activity. This, in turn, could increase the risk of oxidative stress-induced cellular damages. In addition, this study corroborates the use of peripheral blood lymphocytes as an easy handling model for monitoring not only the immune and/or inflammation response, but also the adaptive response to environmental challenge.