caa a22 4500 465735614 CHVBK 20180323111754.0 cr unu---uuuuu 170327e19900601xx s 000 0 eng 10.1007/BF00177352 doi (NATIONALLICENCE)springer-10.1007/BF00177352 Temporal effects of dexamethasone on blood-to-brain and blood-to-tumor transport of 14C-alpha-aminoisobutyric acid in rat C6 glioma [Elektronische Daten] [William Shapiro, Emile Hiesiger, Gail Cooney, George Basler, Lauren Lipschutz, Jerome Posner] Summary: We used quantitative autoradiography (QAR) to evaluate the effect of systemically administered dexamethasone on capillary permeability in brain tumors and surrounding brain. Rats bearing unilateral right hemispheric C6 gliomas were studied at one and twelve hours after 10 mg/kg of intraperitoneal dexamethasone. Capillary permeability was determined by measuring unidirectional blood-to-brain and blood-to-tumor transport of 14C-alpha aminoisobutyric acid (14C-AIB) over fifteen minutes. 14C-AIB entry into tumor, brain adjacent-to-tumor (BAT), and ipsilateral and contralateral cortices was determined and expressed as a unidirectional transfer constant, K. Nontreated tumor K was more than two-fold greater than K for BAT and ten-fold greater than ipsilateral cortical K, confirming substantial barrier disruption in tumor. In addition, the K for BAT was also significantly greater than K for cortex, indicating that the barrier in the peritumoral region was also disrupted. One hour after dexamethasone treatment, tumor K fell to 63% of its pretreatment value (p < 0.025). By twelve hours post-treatment, tumor K fell to 25% of the untreated value (p < 0.001) and to 47% of the one-hour value (p < 0.005). BAT K fell to 29% of its untreated value (p < 0.02) and to 46% of its one-hour value (p < 0.02). By 12 hours, ipsilateral cortical K fell to 67% of the untreated cortical value (p < 0.05). Compared to untreated values, there was no significant difference between contralateral cortical K at either one or twelve hours. Capillary permeability of both C6 brain tumor and normal brain vessels around tumor are increased as measured by blood-to-tissue transport of 14C-AIB. A single dose of dexamethasone reduces capillary permeability as early as one hour after administration in the tumor, then continuously over a twelve-hour time course in both tumor and BAT. Kluwer Academic Publishers, 1990 brain tumors nationallicence blood-brain barrier nationallicence cerebral edema nationallicence corticosteroids nationallicence Shapiro William George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut Hiesiger Emile Department of Neurology, New York University School of Medicine, 10016, New York, NY, USA aut Cooney Gail 1500 North Dixie Highway, Suite 30S, 33401, West Palm Beach, FL, USA aut Basler George George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut Lipschutz Lauren George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut Posner Jerome George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut Journal of Neuro-Oncology Kluwer Academic Publishers 8/3(1990-06-01), 197-204 0167-594X 8:3<197 1990 8 11060 https://doi.org/10.1007/BF00177352 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00177352 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shapiro William George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut NATIONALLICENCE 700 1- Hiesiger Emile Department of Neurology, New York University School of Medicine, 10016, New York, NY, USA aut NATIONALLICENCE 700 1- Cooney Gail 1500 North Dixie Highway, Suite 30S, 33401, West Palm Beach, FL, USA aut NATIONALLICENCE 700 1- Basler George George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut NATIONALLICENCE 700 1- Lipschutz Lauren George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut NATIONALLICENCE 700 1- Posner Jerome George C. Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA aut NATIONALLICENCE 773 0- Journal of Neuro-Oncology Kluwer Academic Publishers 8/3(1990-06-01), 197-204 0167-594X 8:3<197 1990 8 11060 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer