Erschienen in:
01.12.2011 | Original Contribution
Hypovolemic state: age-related influence of water restriction on cardiac nitric oxide synthase in rats
verfasst von:
Andrea Lorena Fellet, Patricia Raquel Arza, Myriam Nuñez, Cristina Teresa Arranz, Ana María Balaszczuk
Erschienen in:
European Journal of Nutrition
|
Ausgabe 8/2011
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Abstract
Aim of study
We have assessed the influence of water restriction stress on the nitric oxide (NO) synthase in heart and aorta tissues in young 2-month-old and middle-aged 12-month-old rats.
Methods
Animals were divided into control and 24- and 72-h water-deprived groups. We evaluated systolic blood pressure (SBP), biochemical parameters, nitrate and nitrite urinary excretion (UNOx), NADPH-diaphorase activity, and protein levels of NOS in the right atria, left ventricle, and thoracic aorta tissues.
Results
Water restriction during 72 h increased SBP (16%) in 2-month-old rats but decreased it after 24 and 72 h (9 and 15%, respectively) in 12-month-old rats. Atria, aorta endothelium, and smooth muscle NOS activity increased (32, 63, and 88%, respectively) only after 72 h of water restriction in 2-month-old rats. It also increased not only after 72 h but also after 24 h in atria (27 and 18%, respectively) and in ventricle (39 and 67%, respectively) in 12-month-old rats. Meanwhile, in this group’s aorta smooth muscle, the enzyme activity decreased (16 and 7%, respectively). A major difference seen between ages was the changes in UNOx excretion, which decreased in the younger in 24 and 72 h (47 and 81%, respectively) and increased in the middle-aged rats (193 and 389%, respectively). Water restriction did not change cardiovascular endothelial and neuronal NOS protein levels in any group.
Conclusion
NO pathways could contribute to the development of age-related cardiovascular adaptation to volume depletion induced by water restriction.