低血容量状态：水限制对大鼠心脏一氧化氮合酶的年龄相关影响。
Hypovolemic state: age-related influence of water restriction on cardiac nitric oxide synthase in rats.
机构信息
Department of Physiology, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD, Buenos Aires, Argentina.
出版信息
Eur J Nutr. 2011 Dec;50(8):657-64. doi: 10.1007/s00394-011-0183-6. Epub 2011 Mar 15.
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.
目的
本研究旨在评估水限制应激对年轻 2 个月大和中年 12 个月大大鼠心脏和主动脉组织中一氧化氮（NO）合酶的影响。
方法
动物分为对照组和 24 小时和 72 小时缺水组。我们评估了收缩压（SBP）、生化参数、硝酸盐和亚硝酸盐尿排泄（UNOx）、NADPH 黄递酶活性以及右心房、左心室和胸主动脉组织中 NOS 的蛋白水平。
结果
72 小时的水限制使 2 个月大的大鼠 SBP 升高（16%），但使 12 个月大的大鼠 SBP 在 24 小时和 72 小时后分别降低（9%和 15%）。仅在 2 个月大的大鼠水限制 72 小时后，心房、主动脉内皮和平滑肌 NOS 活性分别增加（32%、63%和 88%）。在 12 个月大的大鼠中，它不仅在 72 小时后增加，而且在 24 小时后也增加，分别为心房（27%和 18%）和心室（39%和 67%）。同时，在该组的主动脉平滑肌中，酶活性降低（分别为 16%和 7%）。在不同年龄组之间观察到的一个主要差异是 UNOx 排泄的变化，在年轻大鼠中，24 小时和 72 小时分别减少（分别为 47%和 81%），而在中年大鼠中增加（分别为 193%和 389%）。水限制没有改变任何组的心血管内皮和神经元 NOS 蛋白水平。
结论
NO 途径可能有助于因水限制引起的容量耗竭导致的与年龄相关的心血管适应的发展。
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