Charmandari E, Meadows N, Patel M, Johnston A, Benjamin N
Department of Paediatric Gastroenterology, St Bartholomew's and the Royal London School of Medicine, UK.
J Pediatr Gastroenterol Nutr. 2001 Apr;32(4):423-7. doi: 10.1097/00005176-200104000-00006.
In patients with intact renal function and low dietary nitrate intake, plasma nitrate concentrations reflect endogenous nitric oxide production and are shown to be increased during inflammatory processes. The aim of this study was to compare plasma nitrate concentrations and hence endogenous nitric oxide production in children with infectious and noninfectious diarrhea and to determine whether plasma nitrate concentrations could serve as a discriminant test between acute and chronic diarrhea in children.
Three groups of patients were identified: 14 patients with acute gastroenteritis, 13 patients with chronic noninfectious diarrhea, and 14 patients with no evidence of gastrointestinal pathology and no underlying infectious process, who served as control subjects. Plasma nitrate concentrations were determined spectrophotometrically using the Greiss reaction before reduction to nitrite with a copper-coated cadmium column.
Mean plasma nitrate concentrations were 405.3 micromol/L +/- 281.6 micromol/L (standard deviation) in patients with infectious diarrhea, 134.7 micromol/L +/- 77.0 micromol/L in patients with chronic diarrhea, and 54.1 micromol/L +/- 20.1 micromol/L in control subjects (F = 42.6, P < 0.0001; analysis of variance). Plasma nitrate concentrations were significantly higher in the infectious diarrhea group compared with the noninfectious diarrhea and control groups (Student-Newman-Keuls test, P < 0.5).
Although an optimal cutoff concentration cannot be defined, plasma nitrate concentrations in excess of 300 micromol/L are suggestive of an infectious process whereas values less than 100 micromol/L are indicative of noninfectious diarrhea.
在肾功能正常且膳食硝酸盐摄入量低的患者中，血浆硝酸盐浓度反映内源性一氧化氮的产生，并且在炎症过程中会升高。本研究的目的是比较感染性和非感染性腹泻患儿的血浆硝酸盐浓度，从而比较内源性一氧化氮的产生情况，并确定血浆硝酸盐浓度是否可作为儿童急性和慢性腹泻的鉴别检测指标。
确定了三组患者：14例急性胃肠炎患者、13例慢性非感染性腹泻患者以及14例无胃肠道病理证据且无潜在感染过程的患者作为对照。在使用涂铜镉柱将硝酸盐还原为亚硝酸盐之前，采用格里斯反应分光光度法测定血浆硝酸盐浓度。
感染性腹泻患者的平均血浆硝酸盐浓度为405.3微摩尔/升±281.6微摩尔/升（标准差），慢性腹泻患者为134.7微摩尔/升±77.0微摩尔/升，对照组为54.1微摩尔/升±20.1微摩尔/升（F = 42.6，P < 0.0001；方差分析）。与非感染性腹泻组和对照组相比，感染性腹泻组的血浆硝酸盐浓度显著更高（Student-Newman-Keuls检验，P < 0.5）。
虽然无法确定最佳临界浓度，但血浆硝酸盐浓度超过300微摩尔/升提示存在感染过程，而低于100微摩尔/升则提示非感染性腹泻。
