Dallinger S, Bobr B, Findl O, Eichler H G, Schmetterer L
Department of Clinical Pharmacology, University of Vienna, Austria.
Stroke. 1998 May;29(5):997-1001. doi: 10.1161/01.str.29.5.997.
The acetazolamide provocation test is commonly used to study cerebrovascular vasomotor reactivity. On the basis of the effect of a carbonic anhydrase inhibitor in the central nervous system, we hypothesized that acetazolamide may also increase blood flow in the human choroid.
In a placebo-controlled, randomized, double-blind, three-way crossover design, acetazolamide (500 mg or 1000 mg i.v.) or placebo was administered to nine healthy subjects. The effect of acetazolamide was studied at 15-minute intervals for 90 minutes. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation. In addition, mean blood flow velocity and resistive index in the ophthalmic artery were measured with Doppler sonography. In a second study in six healthy subjects, we assessed the effect of acetazolamide (1000 mg i.v.) on intraocular pressure.
Acetazolamide increased fundus pulsation amplitude in a dose-dependent manner (1000 mg: +33%; 500 mg: +20%; P<0.001, ANOVA). The effect of acetazolamide on MFV (1000 mg: +18%; 500 mg: +8%; P=0.003, ANOVA) and RI (1000 mg: -4%; 500 mg: -2%; P=0.006, ANOVA) was less pronounced but also significant. Acetazolamide did not induce any changes in systemic hemodynamic parameters but significantly decreased intraocular pressure (1000 mg: -37%; P<0.0001).
The present data show for the first time that intravenously administered acetazolamide increases choroidal blood flow in humans. This phenomenon therefore indicates that the acetazolamide provocation test may qualify as a tool to investigate ocular vasomotor reactivity in a variety of ocular diseases. Moreover, the increase in choroidal blood flow after carbonic anhydrase inhibition can be expected to contribute to the therapeutic efficacy of carbonic anhydrase inhibitors in glaucoma.
乙酰唑胺激发试验常用于研究脑血管舒缩反应性。基于碳酸酐酶抑制剂在中枢神经系统的作用，我们推测乙酰唑胺可能也会增加人体脉络膜的血流量。
采用安慰剂对照、随机、双盲、三交叉设计，对9名健康受试者静脉注射乙酰唑胺（500毫克或1000毫克）或安慰剂。每隔15分钟研究乙酰唑胺的作用，持续90分钟。用激光干涉测量眼底搏动评估搏动性脉络膜血流量。此外，用多普勒超声测量眼动脉的平均血流速度和阻力指数。在另一项对6名健康受试者的研究中，我们评估了静脉注射乙酰唑胺（1000毫克）对眼压的影响。
乙酰唑胺以剂量依赖方式增加眼底搏动幅度（1000毫克：增加33%；500毫克：增加20%；方差分析，P<0.001）。乙酰唑胺对平均血流速度（1000毫克：增加18%；500毫克：增加8%；方差分析，P=0.003）和阻力指数（1000毫克：降低4%；500毫克：降低2%；方差分析，P=0.006）的作用虽不那么明显，但也具有显著性。乙酰唑胺未引起全身血流动力学参数的任何变化，但显著降低了眼压（1000毫克：降低37%；P<0.0001）。
目前的数据首次表明静脉注射乙酰唑胺可增加人体脉络膜血流量。因此，这一现象表明乙酰唑胺激发试验可能可作为一种工具，用于研究多种眼部疾病中的眼血管舒缩反应性。此外，碳酸酐酶抑制后脉络膜血流量的增加有望有助于碳酸酐酶抑制剂治疗青光眼的疗效。
