Jarden J O, Dhawan V, Moeller J R, Strother S C, Rottenberg D A
Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
Ann Neurol. 1989 Mar;25(3):239-45. doi: 10.1002/ana.410250306.
Blood-to-brain and blood-to-tumor transport rate constants for Rb (K1) and apparent tissue blood volume (Vb) were estimated in 8 patients with primary or metastatic brain tumors before and approximately 6 hours after a 100-mg intravenous bolus injection of dexamethasone using 82Rb and positron emission tomography. Eight additional patients were studied to evaluate test-retest variability and repositioning errors. Six hours following dexamethasone administration tumor K1 (but not Vb) was significantly reduced compared with contralateral control brain regions (p less than 0.03). These data are consistent with our previously published 24-hour-postdexamethasone data and suggest that comparable effects of corticosteroids on brain/tumor capillaries may be observed at 5 to 6 and 24 hours. The time course of dexamethasone-induced alterations in brain/tumor capillary permeability supports the view that these alterations may be responsible for at least some of the antiedema effects of corticosteroids.
利用⁸²Rb和正电子发射断层扫描技术，在8例原发性或转移性脑肿瘤患者静脉推注100毫克地塞米松之前以及注射后约6小时，估算了Rb的血脑转运速率常数（K1）和表观组织血容量（Vb）。另外8例患者参与研究，以评估重测变异性和重新定位误差。地塞米松给药6小时后，与对侧对照脑区相比，肿瘤的K1（而非Vb）显著降低（p<0.03）。这些数据与我们之前发表的地塞米松给药后24小时的数据一致，表明在5至6小时和24小时可能观察到皮质类固醇对脑/肿瘤毛细血管的类似作用。地塞米松诱导的脑/肿瘤毛细血管通透性改变的时间进程支持这样一种观点，即这些改变可能至少部分解释了皮质类固醇的抗水肿作用。
