Urinary nitrite: More than a marker of infection
Urinary nitrite: More than a marker of infection
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DOI：
10.1016/s0090-4295(97)00257-4
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发表时间：
1997-08-01
期刊：
影响因子：
2.1
通讯作者：
Weitzberg, E
中科院分区：
文献类型：
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作者：
Lundberg, JON;Carlsson, S;Weitzberg, E
目标。当亚硝酸盐被酸化时，会形成抑菌气体一氧化氮（NO）。由于细菌硝酸还原酶的活性，受感染的尿液可能含有大量亚硝酸盐，尿液中亚硝酸盐的检测通常用于诊断细菌性膀胱炎。我们试图确定一氧化氮是否是由酸化的含亚硝酸盐的尿液产生的。此外，我们还研究了泌尿病原菌大肠杆菌在酸化的含亚硝酸盐尿液中的生长。方法。从健康对照受试者或受感染的含亚硝酸盐尿液的患者收集尿液，将其酸化并在封闭的注射器中孵育，并添加不同量的亚硝酸盐。 30分钟后，除去顶部空间气体并立即注入化学发光NO分析仪。此外，在摄入维生素C后，在从健康对照受试者收集的尿液中测量NO。在添加不同浓度亚硝酸盐的酸性尿液中孵育2小时后，连续测量对照尿液中的细菌生长10小时。结果。受感染的含亚硝酸盐的尿液在轻度酸化后释放出大量的一氧化氮。如果添加亚硝酸盐，酸化对照尿液中也会释放 NO，并且在维生素 C 存在的情况下，这种释放会大大增强。此外，向酸化尿液中添加亚硝酸盐会显着减少大肠杆菌的生长。结论。我们提出，产生亚硝酸盐的细菌通过提供产生抑菌化合物（如一氧化氮）的底物，在酸性尿液中诱导自身死亡。这种机制可以解释为什么尿液酸化和维生素 C 可以有效治疗菌尿。 (C) 1997，Elsevier Science Inc. 保留所有权利。
Objectives. The bacteriostatic gas nitric oxide (NO) is formed when nitrite is acidified. Infected urine may contain considerable amounts of nitrite as a result: of bacterial nitrate reductase activity, and detection of nitrite in urine is routinely used in the diagnosis of bacterial cystitis. We sought to determine whether NO was generated from acidified nitrite-containing urine. Furthermore, we also studied the growth of the urinary pathogen Escherichia coli in acidified nitrite-containing urine.Methods. Urine, collected from healthy control subjects or from patients with infected nitrite-containing urine, was acidified and incubated in a closed syringe with varying amounts of nitrite added. After 30 minutes, the headspace gas was removed and immediately injected into a chemiluminescence NO analyzer. In addition, NO was measured in urine collected from healthy control subjects after ingestion of vitamin C. Bacterial growth was measured continuously in control urine for 10 hours after incubation for 2 hours in acidic urine with varying concentrations of nitrite added.Results. Large amounts of NO were released from infected nitrite-containing urine after mild acidification. NO was also released from acidified control urine if nitrite was added, and this release was greatly potentiated in the presence of vitamin C. Furthermore, the growth of E. coli was markedly reduced by the addition of nitrite to acidified urine.Conclusions. We propose that nitrite-producing bacteria induce their own death in acidic urine by supplying substrate for generation of bacteriostatic compounds such as NO, This mechanism might explain why urinary acidification and vitamin C may be effective in the treatment of bacteriuria. (C) 1997, Elsevier Science Inc. All rights reserved.