Sugiyama T, Oku H, Ikari S, Ikeda T
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Invest Ophthalmol Vis Sci. 2000 Apr;41(5):1149-52.
To study the effect of a nitric oxide synthase inhibitor on tissue circulation in the optic nerve head (ONH) of conscious rabbits.
N(G)-nitro-L-arginine methyl ester (L-NAME) (1, 10, or 100 mg/kg), D-NAME (10 mg/kg), or physiological saline was administered intravenously to albino rabbits. A quantitative index of blood velocity, the normalized blur (NB), was measured in the ONH by laser speckle tissue circulation analyzer. The intraocular pressure (IOP) and blood pressure (BP) were also measured. L-arginine (10 mg/kg) was intravenously administered 20 minutes after L-NAME (10 mg/kg) injection. Acetylcholine (ACh; 10 microg/kg per minute) was infused for 15 minutes, with or without pretreatment of L-NAME (1 mg/kg).
L-NAME induced a continuous decrease of the NB in a dose-dependent manner, but D-NAME caused no significant change. At 100 mg/kg, L-NAME significantly increased the IOP, mean BP, and ocular perfusion pressure, but the other doses caused no significant changes. When L-arginine was administered after L-NAME injection, the NB returned to its initial level and remained there. Pretreatment with L-NAME inhibited the increase of NB induced by ACh.
These results indicate that nitric oxide regulates basal tissue circulation in the ONH of conscious rabbits and suggest that ACh increases the circulation by promoting nitric oxide synthesis.
研究一氧化氮合酶抑制剂对清醒家兔视神经乳头（ONH）组织循环的影响。
将N（G）-硝基-L-精氨酸甲酯（L-NAME）（1、10或100mg/kg）、D-NAME（10mg/kg）或生理盐水静脉注射给白化家兔。通过激光散斑组织循环分析仪测量ONH中的血流速度定量指标——归一化模糊度（NB）。同时测量眼内压（IOP）和血压（BP）。在注射L-NAME（10mg/kg）20分钟后静脉注射L-精氨酸（10mg/kg）。在有或没有L-NAME（1mg/kg）预处理的情况下，以10μg/kg每分钟的速度输注乙酰胆碱（ACh）15分钟。
L-NAME以剂量依赖性方式导致NB持续下降，但D-NAME未引起显著变化。在100mg/kg时，L-NAME显著升高IOP、平均血压和眼灌注压，但其他剂量未引起显著变化。在注射L-NAME后给予L-精氨酸时，NB恢复到初始水平并保持在该水平。L-NAME预处理抑制了ACh诱导的NB增加。
这些结果表明一氧化氮调节清醒家兔ONH的基础组织循环，并提示ACh通过促进一氧化氮合成增加循环。
