Thesis (M.Phil.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 99-[110]) Also available in print.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2009. / Härtill 4 uppsatser.

Investigators have suggested that opiate peptide hormones released during exercise stress may play an important role in athletic performance or perceived effort. Their enzymatic inactivation in the periphery is of considerable interest since the opiate peptides may be regulated by enkephalin hydrolyzing enzyme (EHA). In this study, the relationship between maximal aerobic capacity (VO_2max) and EHA activity was examined in two distinct fitness groups. When the metabolic capacity was evaluated in whole blood, the unfit subjects metabolized the peptides significantly faster than their fit counterparts. Since the total enzyme activity of the two groups is similar, the difference in metabolism must result from circulating factors in the trained athletes, which slow the rate of peptide inactivation.

Evidence linking the development of chronic alcoholism with endogenous opioid peptides is reviewed. Particular emphasis is placed on enkephalin metabolism with respect to its involvement in the development of addiction and stress-related psychophysiological changes. The study was concerned with enkephalin hydrolysing activity (EHA) in chronic alcoholism as well as the mood changes that reportedly accompany alcoholism. Also of interest was the relationship of enkephalin degradation to voluntary relaxation.