Acute and chronic hyperbaric oxygen exposure in humans: effects on blood polyamines, adrenocorticotropin and β-endorphin

Plasma β-endorphin, adrenocorticotropin (ACTH) and blood polyamine (spermidine and spermine) concentrations were evaluated in healthy adult male athletes undergoing hyperbaric oxygen exposure for 10 days (2.8 atm, 100% O 2 , 60 min daily). in the «acute phase», corresponding to the first day of treatment, and in the «acute in the chronic phase», corresponding to the values obtained on the 5th and 10th days after 60 min of hyperbaric O 2 , both ACTH and β-endorphin levels increased significantly, whereas no variations were observed for polyamine concentrations. In the «chronic phase», corresponding to the basal values of the 5th and 10th days of treatment, we found a different pattern