Uremic levels of BUN do not cause nitric oxide deficiency in rats with normal renal function.
Uremic levels of BUN do not cause nitric oxide deficiency in rats with normal renal function.
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DOI：
10.1152/ajprenal.2001.280.6.f996
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发表时间：
2001-06
期刊：
影响因子：
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通讯作者：
S. Xiao;A. Erdely;L. Wagner;C. Baylis
中科院分区：
文献类型：
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作者：
S. Xiao;A. Erdely;L. Wagner;C. Baylis
体外实验中，7d高血尿素氮(BUN)可抑制血管内皮细胞L-精氨酸转运和一氧化氮合酶(NOS)活性。本研究探讨体内7天高BUN是否影响肾血流动力学、血压(BP)和/或一氧化氮(NO)系统。正常大鼠喂饲含30%尿素的低硝酸盐饲料7d后，BUN由15+/-1增至69+/-4 mg/100ml，P<；0.001。高BUN并不能减少24小时尿亚硝酸盐/硝酸盐排泄量(衡量总NO生成量)。基础血压和肾脏血流动力学不受高BUN的影响，N(G)-硝基-L-精氨酸甲酯对急性一氧化氮合酶抑制的升压和肾血管收缩反应也不受影响。此外，高BUN对肾皮质L-精氨酸浓度、内皮型和神经型一氧化氮合酶蛋白密度以及肾皮质一氧化氮合酶活性均无明显影响。大脑、小脑中的一氧化氮合酶活性也没有受到影响。结论：在肾功能正常的大鼠中，高BUN不会导致血管收缩或NO缺乏。高BUN对进行性肾功能不全大鼠NO系统的影响有待进一步研究。
In vitro, 7 days of high blood urea nitrogen (BUN) inhibits endothelial L-arginine transport and nitric oxide synthase (NOS) activity. The present study investigates whether 7 days of high BUN in vivo influences renal hemodynamics, blood pressure (BP), and/or the nitric oxide (NO) system. Normal rats were fed low-nitrate food containing 30% urea for 7 days, which increased BUN (15 +/- 1 to 69 +/- 4 mg/100 ml, P < 0.001). High BUN did not reduce 24-hour urinary nitrite/nitrate excretion (a measure of total NO production). Baseline BP and renal hemodynamics were unaffected by high BUN as were the pressor and renal vasoconstrictor responses to acute NOS inhibition with N(G)-nitro-L-arginine-methyl ester. In addition, high BUN had no impact on renal cortical L-arginine concentration, density of either endothelial NOS or neuronal NOS protein, or renal cortical NOS activity. NOS activity in the brain cerebellum was also unaffected. In conclusion, high BUN did not lead to vasoconstriction or NO deficiency in rats with normal renal function. Further studies are needed to evaluate the effect of high BUN on the NO system in rats with progressive renal functional insufficiency.