Fischer-Nakielski H, Schrör K
Institut für Pharmakologie, Heinrich-Heine-Universität Düseldorf, FRG.
Stroke. 1990 Dec;21(12 Suppl):IV46-8.
The purpose of this study was to investigate the formation and action of a nitric oxide-related endothelium-derived relaxing factor in cerebral arteries of cattle. Pial artery segments (0.6-1 mm o.d.) were incubated in oxygenated (20%) Krebs-Henseleit buffer containing indomethacin. Addition of acetylcholine (0.1 microM) to rings precontracted by serotonin (0.1 microM) resulted in a significant (p less than 0.05) relaxation. This response disappeared after removal of the endothelium and addition of hemoglobin, a nitric oxide scavenger, and NG-monomethyl-L-arginine, an inhibitor of L-arginine-derived nitric oxide biosynthesis. L-Arginine (10 microM) considerably attenuated the inhibitory action of NG-monomethyl-L-arginine. Relaxations induced by 3-morpholinosydnonimine and nitroglycerin (0.1 microM), two exogenous sources of nitric oxide, were unaffected by NG-monomethyl-L-arginine (10 microM) but abolished by hemoglobin. These data strongly suggest nitric oxide as the mediator of endothelium-derived relaxation in pial arteries of the cattle.
本研究的目的是调查一氧化氮相关的内皮衍生舒张因子在牛脑动脉中的形成及作用。将软脑膜动脉段（外径0.6 - 1毫米）置于含吲哚美辛的充氧（20%）Krebs - Henseleit缓冲液中孵育。向由血清素（0.1微摩尔）预收缩的血管环中加入乙酰胆碱（0.1微摩尔），可导致显著（p小于0.05）的舒张。去除内皮并加入一氧化氮清除剂血红蛋白以及L - 精氨酸衍生的一氧化氮生物合成抑制剂NG - 单甲基 - L - 精氨酸后，该反应消失。L - 精氨酸（10微摩尔）可显著减弱NG - 单甲基 - L - 精氨酸的抑制作用。由一氧化氮的两种外源性来源3 - 吗啉代辛二酮和硝酸甘油（0.1微摩尔）诱导的舒张不受NG - 单甲基 - L - 精氨酸（10微摩尔）影响，但可被血红蛋白消除。这些数据有力地表明一氧化氮是牛软脑膜动脉中内皮衍生舒张的介质。
