Higher antioxidant defences in plasma and low density lipoproteins from rugby players.
BACKGROUND
Even if physical activity constitutes a well-known antiatherogenic factor, the precise mechanisms underlying this protective effect are not completely clear.


METHODS
Lipid and antioxidant profiles were evaluated in 15 well-trained rugby players and 15 sedentary controls. Lipoprotein fractions were separated by sequential ultracentrifugation and alpha-tocopherol content was determined in each fraction by high-performance liquid chromatography. Susceptibility to in vitro oxidation was also measured in intermediate and low density lipoproteins isolated from both groups of subjects as the production of conjugated dienes.


RESULTS
Although the sportsmen were not receiving any special diet or vitamin supplementation they showed a slightly improved lipoprotein profile, mainly represented by increased high density lipoprotein-cholesterol levels (P < 0.05), and an enhanced antioxidant status. The latter was evidenced by an increment in total radical antioxidant potential (P < 0.001), higher ascorbic acid (P < 0.005) and alpha-tocopherol (P < 0.05) plasma concentrations, and elevated activities of superoxide dismutase (P < 0.001) and arylesterase (P < 0.01). Moreover, only the fraction of intermediate and low density lipoproteins from rugby players presented higher alpha-tocopherol content in comparison with sedentary controls (484 +/- 67 vs. 377 +/- 123 microg dL(-1), respectively; P < 0.01). Nevertheless, the susceptibility to in vitro oxidation of this lipoprotein fraction was not different between both groups.


CONCLUSIONS
Given that intermediate density and low density lipoproteins represent the most atherogenic fraction, this finding, in combination with the improved lipid and antioxidant status, would add to the link between regular physical activity and protection against cardiovascular disease.
Evelson
P
P
Cátedra de Química General Inorgánica, Universidad de Buenos Aires, Argentina, Hospital Militar Central, Buenos Aires, Argentina.
Gambino
G
G
Travacio
M
M
Jaita
G
G
Verona
J
J
Maroncelli
C
C
Wikinski
R
R
Llesuy
S
S
Brites
F
F
D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000097:blood; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D016022:Case-Control Studies; D002374:Catalase / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D005538:Football / Q000502:physiology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014810:Vitamin E / Q000097:blood
D000975:Antioxidants; D008076:Cholesterol, HDL; D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D002374:Catalase; D013482:Superoxide Dismutase; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D001205:Ascorbic Acid