Faraci F M, Mayhan W G, Williams J K, Heistad D D
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
Am J Physiol. 1988 Feb;254(2 Pt 2):H286-91. doi: 10.1152/ajpheart.1988.254.2.H286.
The goal of this study was to examine effects of vasoactive stimuli on blood flow to choroid plexus. We used microspheres to measure blood flow to choroid plexus and cerebrum in anesthetized dogs and rabbits. A critical assumption of the microsphere method is that microspheres do not pass through arteriovenous shunts. Blood flow values obtained with simultaneous injection of 15- and 50-micron microspheres were similar, which suggests that shunting of 15-micron microspheres was minimal. Blood flow to choroid plexus under control conditions was 287 +/- 26 (means +/- SE) ml.min-1.100 g-1 in dogs and 385 +/- 73 ml.min-1.100 g-1 in rabbits. Consecutive measurements under control conditions indicated that values for blood flow are reproducible. Adenosine (5 microM.kg-1. min-1 iv) did not alter blood flow to cerebrum but increased blood flow to choroid plexus two- to threefold in dogs and rabbits. Norepinephrine (0.5 micrograms.kg-1.min-1) and phenylephrine (25 micrograms.kg-1.min-1) did not affect blood flow to cerebrum but decreased blood flow to choroid plexus by approximately 50%. We suggest that 1) the microsphere method provides reproducible valid measurements of blood flow to the choroid plexus in dogs and rabbits and 2) vasoactive stimuli may have profoundly different effects on blood flow to choroid plexus and cerebrum.
本研究的目的是检测血管活性刺激对脉络丛血流的影响。我们使用微球测量麻醉犬和兔脉络丛及大脑的血流。微球法的一个关键假设是微球不会通过动静脉分流。同时注射15微米和50微米微球获得的血流值相似，这表明15微米微球的分流极少。对照条件下犬脉络丛的血流为287±26（均值±标准误）ml·min⁻¹·100g⁻¹，兔为385±73 ml·min⁻¹·100g⁻¹。对照条件下的连续测量表明血流值具有可重复性。腺苷（5 μM·kg⁻¹·min⁻¹静脉注射）未改变大脑血流，但使犬和兔脉络丛的血流增加了两到三倍。去甲肾上腺素（0.5微克·kg⁻¹·min⁻¹）和去氧肾上腺素（25微克·kg⁻¹·min⁻¹）不影响大脑血流，但使脉络丛血流减少约50%。我们认为：1）微球法可对犬和兔脉络丛血流进行可重复的有效测量；2）血管活性刺激对脉络丛和大脑血流的影响可能有很大差异。
