Takayama Jun, Tomidokoro Atsuo, Ishii Kiyoshi, Tamaki Yasuhiro, Fukaya Yasuhiro, Hosokawa Tomokazu, Araie Makoto
Eye Clinic, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
Invest Ophthalmol Vis Sci. 2003 Sep;44(9):3977-85. doi: 10.1167/iovs.03-0024.
To investigate the time course of changes in optic nerve head (ONH) circulation after an acute increase in intraocular pressure (IOP), by using the laser speckle method, and to evaluate the effects of a calcium antagonist, the nitric oxide synthetase inhibitor, indomethacin, or sympathetic nerve amputation on the response in ONH circulation after an acute increase in IOP.
In rabbits, the normalized blur (NB) level, a quantitative index of tissue blood velocity in the ONH, was monitored for 60 minutes after an increase in IOP from 20 mm Hg to 40, 50, or 60 mm Hg and for 25 seconds after increase in IOP from 20 mm Hg to 50 or 60 mm Hg with high time resolution. The effects of systemic administration of 1 micro g/kg per hour nilvadipine (a calcium antagonist), 30 mg/kg N(omega)-nitro-L-arginine (L-NAME), or 5 mg/kg indomethacin, or those of sympathetic nerve amputation on the time course of the changes in NB were studied.
NB showed a quick recovery within several seconds after increase in IOP to 40 or 50 mm Hg, whereas no or little recovery occurred after an increase to 60 mm Hg. The nilvadipine treatment significantly increased NB at IOP of 20 mm Hg (baseline NB, P = 0.045) and apparently impaired the recovery of NB after the increase in IOP. After L-NAME administration, baseline NB significantly decreased (P = 0.028), and the NB recovery time was slightly but significantly prolonged (P = 0.012). Indomethacin showed no effects on baseline NB or NB recovery. Sympathetic nerve amputation increased baseline NB (P = 0.027), but did not influence NB recovery.
The current results showed a quick recovery response in the ONH circulation after an acute increase in IOP in rabbits. A calcium antagonist impaired the response. Production of nitric oxide or prostaglandins or the sympathetic nervous system is probably not mainly responsible for the reaction.
通过激光散斑法研究眼内压（IOP）急性升高后视神经乳头（ONH）循环变化的时间进程，并评估钙拮抗剂、一氧化氮合酶抑制剂、吲哚美辛或交感神经切断术对IOP急性升高后ONH循环反应的影响。
在兔中，将IOP从20 mmHg升高至40、50或60 mmHg后，以高时间分辨率监测60分钟视神经乳头组织血流速度的定量指标——归一化模糊（NB）水平；将IOP从20 mmHg升高至50或60 mmHg后，监测25秒的NB水平。研究每小时静脉注射1μg/kg尼伐地平（一种钙拮抗剂）、30 mg/kg N（ω）-硝基-L-精氨酸（L-NAME）或5 mg/kg吲哚美辛，或交感神经切断术对NB变化时间进程的影响。
将IOP升高至40或50 mmHg后，NB在数秒内迅速恢复，而升高至60 mmHg后无恢复或几乎无恢复。尼伐地平治疗在20 mmHg的IOP水平时显著增加NB（基线NB，P = 0.045），并明显损害IOP升高后NB的恢复。给予L-NAME后，基线NB显著降低（P = 0.028），NB恢复时间略有但显著延长（P = 0.012）。吲哚美辛对基线NB或NB恢复无影响。交感神经切断术增加基线NB（P = 0.027），但不影响NB恢复。
目前的结果显示兔IOP急性升高后ONH循环有快速恢复反应。钙拮抗剂损害该反应。一氧化氮或前列腺素的产生或交感神经系统可能不是该反应的主要原因。
