Duong T Q, Iadecola C, Kim S G
Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota School of Medicine, Minneapolis, Minnesota 55455, USA.
Magn Reson Med. 2001 Jan;45(1):61-70. doi: 10.1002/1522-2594(200101)45:1<61::aid-mrm1010>3.0.co;2-8.
The assessment of cerebral interstitial oxygen tension (piO(2)) can provide valuable information regarding cerebrovascular physiology and brain function. Compartment-specific cerebral piO(2) was measured by (19)F NMR following the infusion of an oxygen-sensitive perfluorocarbon directly into the interstitial and ventricular space of the in vivo rat brain. (19)F T(1) measurements were made and cerebral piO(2) were obtained through in vitro calibrations. The effects of graded hyperoxia, hypercapnia, and hypoxia on piO(2) and cerebral blood flow (CBF) were investigated. Under normoxia (arterial pO(2) approximately 120 mm Hg), piO(2) was approximately 30 mm Hg and jugular venous pO(2) was approximately 50 mm Hg. During hyperoxia (arterial pO(2) = 90-300 mm Hg), piO(2) increased linearly with the arterial pO(2). Following hypercapnia (arterial pCO(2) = 20-60 mm Hg), the piO(2) increased sigmoidally with increasing CBF. With hypoxia (arterial pO(2) = 30-40 mm Hg), CBF increased approximately 56% and piO(2) decreased to approximately 15 mm Hg. The hypoxia-induced CBF increase was effective to some extent in compensating for the reduced piO(2). This methodology may prove useful for investigating cerebral piO(2) under pathologically or functionally altered conditions. Magn Reson Med 45:61-70, 2001.
脑间质氧张力（piO₂）的评估可为脑血管生理学和脑功能提供有价值的信息。通过将氧敏感全氟化碳直接注入活体大鼠脑的间质和脑室空间后，利用¹⁹F核磁共振测量特定区域的脑piO₂。进行¹⁹F T₁测量，并通过体外校准获得脑piO₂。研究了分级高氧、高碳酸血症和低氧对piO₂和脑血流量（CBF）的影响。在常氧（动脉pO₂约120 mmHg）下，piO₂约为30 mmHg，颈静脉pO₂约为50 mmHg。在高氧期间（动脉pO₂ = 90 - 300 mmHg），piO₂随动脉pO₂呈线性增加。高碳酸血症后（动脉pCO₂ = 20 - 60 mmHg），piO₂随CBF增加呈S形增加。在低氧（动脉pO₂ = 30 - 40 mmHg）时，CBF增加约56%，piO₂降至约15 mmHg。低氧诱导的CBF增加在一定程度上有效地补偿了降低的piO₂。这种方法可能被证明对研究病理或功能改变条件下的脑piO₂有用。《磁共振医学》45:61 - 70, 2001。
