Influence of Altitude and Caffeine during Rest and Exercise on Plasma Levels of Proenkephalin Peptide F

摘要

The purpose of the study was to examine the resting and exercise response patterns of plasma Peptide F immunoreactivity (ir) to altitude exposure (4300m) and caffeine ingestion (4mg.KgBW-1). Nine healthy male subjects performed exercise tests to exhaustion at sea level, during an acute altitude exposure (1 hr. hypobaric chamber) and after a chronic (17 day sojourn) altitude exposure. Using a randomized, double-blind/placebo experimental design, a placebo or caffeine drink was ingested 1 hour prior to exercise. Exercise (without caffeine) significantly (p<0.05) increased plasma Peptide F ir values during exercise at chronic altitude only. Caffeine ingestion significantly increased plasma Peptide F ir concentrations during exercise an in the post-exercise period at sea level. Conversely, caffeine ingestion at altitude resulted in significant reductions in the post-exercise plasma Peptide F ir values. The results of this study demonstrate that the exercise and recovery response patterns of plasma Peptide F ir may be significantly altered by altitude exposure and caffeine ingestion. These data support further study examining relationships between Peptide F (and other ECPs) and epinephrine release in response to these types of physiological stresses.