Centro de Investigaciones Biomédicas-Doctorado en Ciencias Biomédicas, Facultad de Ciencias Químicas, Universidad Veracruzana, Xalapa, México.
J Hum Hypertens. 2013 Jun;27(6):355-61. doi: 10.1038/jhh.2012.55. Epub 2012 Dec 6.
Pregnancy is a state of vasodilation mediated by nitric oxide (NO). This vasodilation is impaired in women with preeclampsia, and an alteration in the L-arginine-NO pathway may be a causal factor. The production of NO and arginase activity were investigated in plasma and human umbilical vein endothelial cells (HUVECs) from women with preeclampsia, which were associated with arginase II, eNOS, caveolin, angiotensin 1 and 2 receptor expression (AT1R and AT2R, respectively). The effect of (-)-epicatechin on arginase activity and production of anion superoxide in HUVEC also were investigated. Healthy volunteer non-pregnant (HV), normal pregnant (NP) and preeclamptic (PE) women were recruited for this study. Higher values of nitrite/nitrate (NO(2)/NO(3)) were detected in the plasma from PE women as opposed to HV and NP. Lower arginase activity in PE versus HV or NP women was observed. HUVECs from PE women showed lower values of NO(2)/NO(3), higher activity of arginase and higher expression of AT(1)R and AT(2)R than HUVECS from NP women. Interestingly, arginase activity was associated with AT(2)R stimulation; indeed this activity and the high NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activity in HUVECs from PE women can uncouple the production or inactivation of NO. However, we demonstrated that (-)-epicatechin could lead to a decrease in the activity of both enzymes.
妊娠是一氧化氮（NO）介导的血管扩张状态。这种血管扩张在子痫前期妇女中受损，L-精氨酸-NO 途径的改变可能是一个因果因素。研究了子痫前期妇女血浆和人脐静脉内皮细胞（HUVEC）中 NO 的产生和精氨酸酶活性，以及与精氨酸酶 II、eNOS、 caveolin、血管紧张素 1 和 2 受体表达（AT1R 和 AT2R）相关的活性。还研究了（-）-表儿茶素对 HUVEC 中精氨酸酶活性和阴离子超氧阴离子产生的影响。本研究招募了健康志愿者非妊娠（HV）、正常妊娠（NP）和子痫前期（PE）妇女。与 HV 和 NP 妇女相比，PE 妇女的血浆中亚硝酸盐/硝酸盐（NO2/NO3）值更高。与 HV 或 NP 妇女相比，PE 妇女的精氨酸酶活性更低。PE 妇女的 HUVEC 中 NO2/NO3 值较低，精氨酸酶活性较高，AT1R 和 AT2R 的表达也较高。有趣的是，精氨酸酶活性与 AT2R 刺激有关；事实上，这种活性和 PE 妇女 HUVEC 中高 NADPH（烟酰胺腺嘌呤二核苷酸磷酸）氧化酶活性可使 NO 的产生或失活解偶联。然而，我们证明（-）-表儿茶素可导致两种酶的活性降低。
