Nitric oxide synthase: an endogenous source of elevated nitrite in infected urine.
Nitric oxide synthase: an endogenous source of elevated nitrite in infected urine.
复制标题
一氧化氮合酶：受感染尿液中亚硝酸盐升高的内源性来源。
DOI：
10.1038/ki.1994.76
复制
发表时间：
1994
影响因子：
19.6
通讯作者：
Weiss,RM
中科院分区：
文献类型：
--
作者：
Smith,SD;Wheeler,MA;Weiss,RM
一氧化氮合酶：感染尿液中亚硝酸盐升高的内源性来源。为了进一步确定尿路感染中尿亚硝酸盐的内源性来源，我们采用Griess法测定了尿亚硝酸盐水平，并通过14 C-精氨酸转化为14 C-瓜氨酸测定了尿一氧化氮（NO）合酶活性。14 C-瓜氨酸的内源性产生通过薄层色谱法证实。外源性L-精氨酸增加亚硝酸盐的生产在整个感染的尿液，但不从感染的尿液中分离出的细菌。尿路感染显着增加NO合酶活性可溶性尿组分，虽然可溶性活性小于10%的颗粒活性。来自非感染尿液的女性的尿液颗粒组分比来自非感染尿液的男性的颗粒组分具有更高的NO合成酶活性，分别为11 ± 2和0.2 ± 0.1皮摩尔/分钟/毫克蛋白。尿路感染增加了女性和男性尿颗粒组分中的NO合酶活性，分别为99 ± 20和48 ± 9皮摩尔/分钟/毫克蛋白。14 C-精氨酸转化为14 C-瓜氨酸需要NADPH，不依赖钙，L-刀豆氨酸的抑制程度大于NG-单甲基-L-精氨酸或NG-硝基-L-精氨酸。人感染的尿液含有NO合酶的同种型，其是尿亚硝酸盐的内源性来源。
Nitric oxide synthase: An endogenous source of elevated nitrite in infected urine. To further define the endogenous sources of urine nitrite in urinary tract infections, we measured urinary nitrite levels by the Griess method and assayed urinary nitric oxide (NO) synthase activity by the conversion of14C-arginine to14C-citrulline. Endogenous production of14C-citrulline was confirmed by thin layer chromatography. Exogenous L-arginine increased nitrite production in whole infected urine, but not in bacteria isolated from infected urine. Urinary tract infections significantly increased NO synthase activity in soluble urine fractions, although soluble activity was less than 10% of particulate activity. Urine particulate fractions from women with non-infected urine had greater NO synthase activity than particulate fractions from men with non-infected urine, 11 ± 2 and 0.2 ± 0.1 picomol/min/mg protein, respectively. Urinary tract infections increased NO synthase activity in urine particulate fractions from women and men, 99 ± 20 and 48 ± 9 picomol/min/mg protein, respectively. The conversion of14C-arginine to14C-citrulline required NADPH, was calcium independent, and was inhibited to a greater extent by L-canavanine than by NG-monomethyl-L-arginine or NG-nitro-L-arginine. Human infected urine contains an isoform of NO synthase which is an endogenous source of urine nitrite.