Determination of asymmetric dimethylarginine, an endogenous nitric oxide synthase inhibitor, in umbilical blood.
Determination of asymmetric dimethylarginine, an endogenous nitric oxide synthase inhibitor, in umbilical blood.
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DOI：
10.1016/j.metabol.2007.09.003
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发表时间：
2008-02
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影响因子：
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通讯作者：
H. Tsukahara;N. Ohta;Shuko Tokuriki;K. Nishijima;F. Kotsuji;H. Kawakami;Norihito Ohta;Kyouichi Sekine;H. Nagasaka;M. Mayumi
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文献类型：
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作者：
H. Tsukahara;N. Ohta;Shuko Tokuriki;K. Nishijima;F. Kotsuji;H. Kawakami;Norihito Ohta;Kyouichi Sekine;H. Nagasaka;M. Mayumi
内皮细胞产生一氧化氮（NO），一种有效的血管扩张剂。不对称二甲基精氨酸（ADMA）是一种内源性NO合成酶抑制剂。关于ADMA在围产期环境中的潜在生理作用知之甚少。本研究使用酶联免疫吸附测定法测量脐带血中ADMA的浓度，使用Griess测定法测量NO（亚硝酸盐/硝酸盐）的浓度。他们的关系，早产的程度和产妇的临床条件进行检查。结果显示，对照新生儿脐带血中ADMA浓度约为哺乳期妇女、健康儿童和健康成人的两倍。对照组新生儿脐静脉血中NOx-浓度约为哺乳期妇女、健康儿童和健康成人的一半。因此，对照新生儿的脐带血中ADMA相对于NOx-的水平比哺乳期妇女、健康儿童和健康成人的血液高出约4倍。此外，新生儿的脐带血ADMA浓度和ADMA与NOx−的比率根据其出生早产和出生体重较低而较高。脐带血ADMA浓度与分娩方式和母体先兆子痫无关。我们推断，高水平的ADMA在维持血管张力和血液重新分配到出生时的重要器官中发挥生理作用，从而有利于从胎儿到新生儿生命的循环过渡。
Endothelial cells produce nitric oxide (NO), a potent vasodilator. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. Little is known about the potential physiological roles of ADMA in a perinatal setting. This study measures concentrations of ADMA in umbilical blood using enzyme-linked immunosorbent assay and those of NO as nitrite/nitrate (NOx−) using the Griess assay. Their relationship to the degree of prematurity and maternal clinical condition is examined. Results show that ADMA concentrations in umbilical blood from control newborns were about twice as high as those of lactating women, healthy children, and healthy adults. Umbilical blood NOx−concentrations from control newborns were about half of those of lactating women, healthy children, and healthy adults. Consequently, the levels of ADMA relative to NOx−were about 4-fold higher in umbilical blood from control newborns than in blood from lactating women, healthy children, and healthy adults. Furthermore, the umbilical blood ADMA concentrations and the ratios of ADMA to NOx−in newborns were higher according to their birth prematurity and lower birth weight. The umbilical ADMA concentrations were independent of the delivery mode and maternal preeclampsia. We infer that the high ADMA levels play physiological roles in maintaining vascular tone and blood redistribution to vital organs during birth, thereby favoring the circulatory transition from fetal to neonatal life.