title: Concurrent measurements of blood flow and transcapillary transport in xenotransplanted human gliomas in immunosuppressed rats.
abstract: Neonatal Fischer 344 rats were immunosuppressed with antithymocyte serum and later were given an injection intracerebrally of cells from the human glioma permanent line D-54MG. Symptomatic tumor-bearing rats were studied with double-label quantitative autoradiography to concurrently measure blood flow and a unidirectional blood-to-tissue transfer constant (K) for alpha-aminoisobutyric acid (AIB). A net extraction fraction (En) was calculated from the measured values for blood flow and K. Mean whole tumor blood flow was 53.5 +/- 4.9 ml/100 g/min (mean +/- SEM), which was significantly less than the blood flow to the tumor-free cortex (198 +/- 15.5 ml/100 g/min) but not significantly different from the blood flow in the tumor-free corpus callosum (50.6 +/- 4.3 ml/100 g/min). Mean whole tumor K-value for AIB was 5.8 +/- 0.5 ml/100 g/min, approximately 30 times the K-value for tumor-free brain. The calculated mean whole tumor En was 0.2 +/- 0.09, nearly 100 times the value for the tumor-free brain. Regionally, blood flow was lower in the tumor center and higher in its tumor periphery, although the difference was not significant. Both K- and En-values were significantly higher for the tumor center and decreased radially for the areas from center out. The values for K and En of AIB in the D-54MG gliomas are the highest of any experimental brain tumor model studied to date and indicate that in some tumor regions in this model, blood-to-tissue transport of the water-soluble compound AIB may be dependent on blood flow as well as on the permeability-surface area product of the tumor capillaries.
mesh_terms: D000613:Aminobutyrates / Q000378:metabolism; D000818:Animals; D001345:Autoradiography / Q000379:methods; D001783:Blood Flow Velocity; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism*; D002199:Capillary Permeability; D002460:Cell Line; D004195:Disease Models, Animal; D005910:Glioma / Q000098:blood supply / Q000378:metabolism*; D006801:Humans; D007165:Immunosuppression Therapy; D007700:Kinetics; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D000613:Aminobutyrates; C012223:alpha-aminobutyric acid