Chodobski A, Szmydynger-Chodobska J, Epstein M H, Johanson C E
Department of Clinical Neurosciences, Brown University/Rhode Island Hospital, Providence 02903.
J Cereb Blood Flow Metab. 1995 Jan;15(1):143-51. doi: 10.1038/jcbfm.1995.16.
The effect of peripherally administered angiotensin II (AII) on blood flow to choroid plexuses was examined in pentobarbital-anesthetized rats. The indicator fractionation method with 123I- or 125I-N-isopropyl-p-iodoamphetamine as the marker was employed to measure blood flow. Basal blood flow to choroid plexus of the lateral cerebral ventricle (LVCP) (3.19 +/- 0.23 ml g-1 min-1) was lower than that to choroid plexuses of the third (3VCP) and fourth (4VCP) ventricles (3.90 +/- 0.38 and 3.95 +/- 0.36 ml g-1 min-1, respectively). The effect of AII on choroidal blood flow varied depending on peptide dose and anatomical location of the choroidal tissue. AII infused intravenously at rates of 30 and 50 ng kg-1 min-1 decreased blood flow to both LVCP and 4VCP by 12-20%. Both lower (10 ng kg-1 min-1) and higher (100 and 300 ng kg-1 min-1) AII doses did not alter blood flow to LVCP and 4VCP. Blood flow to the 3VCP was not affected by any dose of the peptide used. In comparison, blood flow to cerebral cortex increased by 33% during intravenous AII infusion at a rate of 300 ng kg-1 min-1. The choroidal blood flow-lowering effect of moderate AII doses was abolished by both AT1 (losartan) and AT2 (PD 123319) receptor subtype antagonists (3 mg kg-1 i.v.). To determine whether the hemodynamic changes observed in choroid plexuses with moderate AII doses influence CSF formation, the ventriculocisternal perfusion was performed in rats (under the experimental conditions described) with Blue Dextran 2000 as the indicator.(ABSTRACT TRUNCATED AT 250 WORDS)
在戊巴比妥麻醉的大鼠中，研究了外周给予血管紧张素II（AII）对脉络丛血流量的影响。采用以123I或125I-N-异丙基-p-碘安非他明为标记物的示踪剂分离法来测量血流量。大脑侧脑室脉络丛（LVCP）的基础血流量（3.19±0.23 ml g-1 min-1）低于第三脑室（3VCP）和第四脑室（4VCP）脉络丛的基础血流量（分别为3.90±0.38和3.95±0.36 ml g-1 min-1）。AII对脉络丛血流量的影响因肽剂量和脉络丛组织的解剖位置而异。以30和50 ng kg-1 min-1的速率静脉注射AII可使LVCP和4VCP的血流量降低12%-20%。较低剂量（10 ng kg-1 min-1）和较高剂量（100和300 ng kg-1 min-1）的AII均未改变LVCP和4VCP的血流量。所用任何剂量的该肽均未影响3VCP的血流量。相比之下，以300 ng kg-1 min-1的速率静脉注射AII期间，大脑皮质的血流量增加了33%。中等剂量AII降低脉络丛血流量的作用可被AT1（氯沙坦）和AT2（PD 123319）受体亚型拮抗剂（3 mg kg-1静脉注射）消除。为了确定中等剂量AII在脉络丛中观察到的血流动力学变化是否影响脑脊液生成，在大鼠中（在所述实验条件下）以蓝色葡聚糖2000为指示剂进行了脑室池灌注。（摘要截短于250字）
