5-hydroxytryptamine evokes endothelial nitric oxide synthase activation in bovine aortic endothelial cell cultures.
5-hydroxytryptamine evokes endothelial nitric oxide synthase activation in bovine aortic endothelial cell cultures.
复制标题
5-羟色胺在牛主动脉内皮细胞培养物中引起内皮一氧化氮合酶活化。
DOI：
10.1046/j.1525-1373.1999.d01-97.x
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Maleque,MA
中科院分区：
文献类型：
--
作者：
McDuffie,JE;Coaxum,SD;Maleque,MA
内皮一氧化氮合酶（eNOS）的激活导致一氧化氮（NO）的产生，介导内皮细胞的血管舒张特性。本项目的目标是解决5-羟色胺（5-HT）刺激牛主动脉内皮细胞（BAEC）培养物中eNOS活性的可能性。在此，我们通过测量BAEC培养物中激动剂刺激的[3H] L-瓜氨酸（[3H] L-Cit）形成来检验5-HT受体介导eNOS活化的假设。我们发现5-HT刺激[3H] L-精氨酸（[3H] L-Arg）转化为[3H] L-Cit，表明eNOS激活。高亲和力5-HT1B受体激动剂5-壬氧基色胺（5-NOT）刺激的[3H] L-Cit转换反应具有浓度（0.01 nM至100 μ M）和时间依赖性。在激动剂暴露后10分钟内观察到最大反应。这些反应可被5-HT1B受体拮抗剂艾沙莫坦、5-HT1B/5-HT2受体拮抗剂甲硫替平和eNOS选择性拮抗剂（0.01 - 10 μ M）：L-N ω-单甲基-L-精氨酸（L-NMMA）和L-N ω-亚氨基乙基-L-鸟氨酸（L-NIO）有效阻断。用百日咳毒素（PTX; 1 - 100 ng/ml）预处理BAEC培养物16小时导致激动剂刺激的eNOS活性的显著抑制，表明G蛋白的参与。这些发现提供了5-HT 1B受体/eNOS通路的证据，部分解释了5-HT激活eNOS的原因。需要进一步研究以确定其他血管5-HT受体在刺激eNOS活性中的作用。
Activation of endothelial nitric oxide synthase (eNOS) results in the production of nitric oxide (NO) that mediates the vasorelaxing properties of endothelial cells. The goal of this project was to address the possibility that 5‐hydroxytryptamine (5‐HT) stimulates eNOS activity in bovine aortic endothelial cell (BAEC) cultures. Here, we tested the hypothesis that 5‐HT receptors mediate eNOS activation by measuring agonist‐stimulated [3H]L‐citrulline ([3H]L‐Cit) formation in BAEC cultures. We found that 5‐HT stimulated the conversion of [3H]L‐arginine ([3H]L‐Arg) to [3H]L‐Cit, indicating eNOS activation. The high affinity 5‐HT1Breceptor agonist, 5‐nonyloxytryptamine (5‐NOT)‐stimulated [3H]L‐Cit turnover responses were concentration‐(0.01 nMto 100 μM) and time‐dependent. Maximal responses were observed within 10 min following agonist exposures. These responses were effectively blocked by the 5‐HT1Breceptor antagonist, isamoltane, the 5‐HT1B/5‐HT2receptor antagonist, methiothepin, and the eNOS selective antagonists (0.01–10 μM): L‐Nω‐monomethyl‐L‐arginine (L‐NMMA) and L‐Nω‐iminoethyl‐L‐ornithine (L‐NIO). Pretreatment of BAEC cultures with pertussis toxin (PTX; 1–100 ng/ml) for 16 hr resulted in significant inhibition of the agonist‐stimulated eNOS activity, indicating the involvement of Giproteins. These findings lend evidence of a 5‐HT1Breceptor/eNOS pathway, accounting in part for the activation of eNOS by 5‐HT. Further investigation is needed to determine the role of other vascular 5‐HT receptors in the stimulation of eNOS activity.