Responses of Plasma Atrial Natriuretic Peptide to High Intensity Submaximal Exercise in the Heat

摘要

No data exists regarding human response of atrial natriuretic peptide (ANP) to exercise in the heat. The purpose of this study was to examine the responses of plasma ANP to high intensity submaximal (71% + or - 0.9 VO2MAX) exercise in the heat over an eight day acclimation period. Fourteen healthy males volunteered to participate in the study. Subjects performed intermittent exercises on a treadmill (0% grade) during 50 min of each 100 min trial in an environmental chamber maintained at 41.2 + or - 0.5C, 39.0 + or - 1.7% relative humidity. Blood was obtained from an antecubital vein after standing 20 min in the heat prior to exercise, and immediately after exercise was completed on days 1,4 and 8. ANP did not change pre- to post-exercise nor did it change over the eight day heat acclimation period despite other heat acclimation adaptations. Conversely, plasma aldosterone (ALDO), renin activity (PRA) and cortisol (COR) all increased (p less than 0.05) pre- to post-exercise on each day but again no changes were observed over the eight day period. These data support that ANP may not increase when ALDO and PRA increases.