title: Concomitant increase in blood plasma levels of immunoreactive hemorphin-7 and beta-endorphin following long distance running.
abstract: Hemorphins are endogenous opioids derived by enzymatic degradation of hemoglobin, a protein released in blood plasma during long distance running. We examined levels of beta-endorphin and the heptapeptide hemorphin-7, in heparinized venous blood plasma from 15 sedentary controls (8 males, 7 females) and from 15 age- and sex-matched marathon runners at baseline and after running 42 km or 21 km. Baseline levels of beta-endorphin (range 0.2-4.3 fmol/ml) were neither dependent upon weight, body mass index weight/height, running status nor sex. Baseline levels of hemorphin-7 (range 0.2-6.9 pmol/ml) were lower in women (P < 0.04) and covariated positively with body weight (P = 0.06), explaining lower levels in runners by their lower body weight. Covariation with body mass index was positive, but not significant (P = 0.10), however, here the dependence upon sex appeared stronger (P = 0.014). Running induced significant and correlated increases in hemorphin-7 and beta-endorphin (r = 0.74; P < 0.002), possibly indicating a functional relationship between these two peptides.
authors.affiliation: Department of Pharmaceutical Biosciences, University of Uppsala, Sweden.
authors.forename: E L
authors.initials: EL
authors.lastname: Glämsta
authors.forename: L
authors.initials: L
authors.lastname: Mørkrid
authors.forename: I
authors.initials: I
authors.lastname: Lantz
authors.forename: F
authors.initials: F
authors.lastname: Nyberg
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D018377:Neurotransmitter Agents / Q000097:blood*; D010446:Peptide Fragments / Q000378:metabolism*; D011863:Radioimmunoassay / Q000379:methods; D012420:Running / Q000502:physiology*; D012727:Sex Characteristics; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D006454:Hemoglobins; D018377:Neurotransmitter Agents; D010446:Peptide Fragments; C085122:hemorphin 7; D001615:beta-Endorphin