Vol. 276, Issue 3, H970-H975, March 1999
Hypotension induced by exercise is associated with enhanced
release of adenyl purines from aged rat artery
M.
Hashimoto1,
K.
Shinozuka2,
Y.
Tanabe1,
S.
Gamoh1,
T.
Hara1,
M. S.
Hossain1,
Y. M.
Kwon2,
M.
Kunitomo2, and
S.
Masumura1
1 Department of Physiology,
Shimane Medical University, Izumo, Shimane 693-8501; and
2 Department of Pharmacology,
Faculty of Pharmaceutical Science, Mukogawa Women's University,
Nishinomiya 663-8179, Japan
To determine
whether the antihypertensive effects of exercise are associated with
release of ATP and its metabolites from arteries, we assayed blood
pressure and the release of adenine nucleotides and nucleosides from
the caudal arteries of exercised and sedentary aged
hypercholesterolemic rats. Exercise on a treadmill for 12 wk
significantly decreased the rise in systolic and diastolic blood
pressure by 7.5 and 15.9%, respectively, with advanced age. The
concentrations of oleic, linoleic, and linolenic acids in the caudal
artery decreased significantly with exercise, demonstrating an
association between exercise and the unsaturation index of caudal
arterial fatty acids. The amounts of total adenyl purines released by
the arterial segments from exercised rats, both spontaneously and in
response to norepinephrine, were significantly greater by 80.0 and
60.7%, respectively, than those released by tissues from sedentary
rats. These results suggest that exercise alters the membrane fatty
acid composition in aged rats as well as the release of ATP from
vascular endothelial cells and that these factors are associated with
the regression of the rise in blood pressure normally observed with
advanced age.
adenosine 5'-triphosphate release; blood pressure; arterial
fatty acids
