左旋-硝基精氨酸甲脂对急性高眼压状态下大鼠视网膜的影响

目的通过对大鼠实验前给予左旋-硝基精氨酸甲脂（L—NAME，NO前体左旋精氨酸类似物）后。观察急性高眼压后大鼠视网膜电图（ERG）b波幅的变化，iNOSmRNA的表达情况。探讨L-NAME和i—NOS在高眼压视网膜损伤中的作用。方法Wister大鼠48只随机分为6组，分别为高眼压30min、90min组、高眼压后12h组、注射L—NAME＋高眼压30min、90min组和注射L—NAME＋高眼压后12h组。前房加压灌注成高眼压模型。Alnplaldamk 15型视电生理仪检测FERG—b波波幅变化。RT—PcR法检测iNOSmRNA的表达。结果L—NAME组的ERG—b波波幅与对照组相比前者明显恢复（P〈0．01）。高眼压30min，90min，12hiNOSmRNA的表达逐渐增强，但L-NAME组中iNOSmRNA的表达明显低于对应的高眼压组（P〈0．01）。结论L—NAME做为一氧化氮合酶的抑制剂，通过抑制iNOS合成具有细胞毒性的NO，有助于缺血后的视网膜功能的恢复，对视网膜起到保护作用。

Effect of L-NAME on retina of rats with acute intraocular hypertension

[Objective] To investigate the effect of L-NAME and induced nitric oxide synthase (iN0S) in rat retinal damage under hypertension. [Methods] 48 Wistar rats were divided into six groups randomly comprising:ocular hypertension 30 min, 90 min, 12h after reperfusion, injection L-NAME+ hypertension 30 min, injection L-NAME+ hypertension 90 min, and injection L-NAME+12 h after reperfusion, seperately. Elevation of the ocular pressure in the anterior chamber of the rat eye caused retina ischemic damage. Then b-wave of ERGs and expression of iNOS mRNA were recorded by RT-PCR. [Results] Pretreatment with intravenous L-NAME greatly enhanced b-wave amplitude (P ＜0.01) compared with the groups of hypertension. The expression of iNOS mRNA was lower than that of untreated groups. [Conclusion] As an inhibitor of iNOS, L-NAME may play an important role in protecting retina from ischemic and post-ischemic injury.