Plasma Opioid Peptide Responses during Heat Acclimation in Humans
Abstract
Plasma Beta-endorphin, Metenkephalin and Peptide F immunoreactivity (ir) were measured at rest and following exercise on three days of an eight day heat acclimation regime. Fourteen male subjects demonstrated physiological heat acclimation adaptations. Our data demonstrated a differential response of peripheral plasma levels of endogenous opioid peptides (EOP) to exercise in the heat. In addition, EOP did not follow the same time-course of other physiological adaptations as no differences in resting or exercise levels were observed over the eight day heat acclimation regime. Significant increases in Beta-endorphin ir (pre- to post-exercise) appear to reflect concomitant exercise-heat related changes. The increased peripheral levels of Beta-endorphin were correlated to plasma levels of cortisol. Heat and exercise stress may result in a reduction of Metenkephalin is observed in peripheral plasma and might be due to degradation or a decrease in processing from the larger precursors. The differential responses of EOP suggest the possibility of separate physiological roles for these peptides during exercise in the heat but peripheral plasma levels of EOP do not appear to reflect acute heat acclimation changes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1987
- Accession Number
- ADA185348
Entities
People
- Lawrence E. Armstrong
- Louis J. Marchitelli
- Natalie Leva
- Roger W. Hubbard
- William J. Kraemer
Organizations
- United States Army Research Institute of Environmental Medicine