title: Preliminary study of the relationship between plasma and erythrocyte magnesium variations and some circulating pro-oxidant and antioxidant indices in a standardized physical effort.
abstract: The aim of this preliminary study was to determine the relationship between exercise, magnesium (Mg) status, oxidative stress, and antioxidant defence systems. Some corresponding indices have been evaluated: plasma Mg, ascorbate, uric acid, adrenaline, creatine kinase (CK), thiobarbiturate reactive substances, adrenochrome; and in erythrocytes (RBC): reduced and oxidized glutathione (GSH and GSSG) and Mg. Venous blood samples were withdrawn before and 3 min after completion of a 40 min run. Only two significant changes were observed after effort: plasma Mg decreased (P < 0.009) and plasma adrenaline increased (P < 0.005). There was a non-significant tendency for indices of oxidative stress and antioxidant capacity to increase. The significant correlations between plasma Mg and CK (r = -0.88) and between RBC Mg and plasma ascorbate (r = -0.76) disappeared after the effort. Further research is necessary, with a larger number of subjects and variables, to obtain a better understanding of these interactions.
authors.affiliation: Laboratory of Biochemistry, Faculty of Human Motricity, Technical University, Lisbon, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Laires
authors.forename: F
authors.initials: F
authors.lastname: Madeira
authors.forename: J
authors.initials: J
authors.lastname: Sérgio
authors.forename: C
authors.initials: C
authors.lastname: Colaço
authors.forename: C
authors.initials: C
authors.lastname: Vaz
authors.forename: G M
authors.initials: GM
authors.lastname: Felisberto
authors.forename: I
authors.initials: I
authors.lastname: Neto
authors.forename: L
authors.initials: L
authors.lastname: Breitenfeld
authors.forename: M
authors.initials: M
authors.lastname: Bicho
authors.forename: C
authors.initials: C
authors.lastname: Manso
mesh_terms: D000328:Adult; D000975:Antioxidants; D001205:Ascorbic Acid / Q000097:blood; D004837:Epinephrine / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005978:Glutathione / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008274:Magnesium / Q000097:blood*; D008297:Male; D010084:Oxidation-Reduction
chemical_list: D000975:Antioxidants; D005978:Glutathione; D008274:Magnesium; D001205:Ascorbic Acid; D004837:Epinephrine