Effect of carbogen breathing on the physiological profile of human glioma xenografts.
The aim of this study was to evaluate the effect of carbogen breathing on the physiological profile of human glioma xenografts. Near infrared spectroscopy was used to investigate changes in oxy- and deoxyhemoglobin concentrations in tumor blood. Oxygen tension changes in tumor tissue were evaluated by (19)F-MR relaxometry, using perfluoro-15-crown-5-ether, and modifications of tumor blood perfusion (TBP) were analyzed by fast dynamic (1)H-MR imaging of Gd-DTPA uptake. Finally, changes of the bioenergetic status and pH of tumor cells were analyzed by (31)P-MRS. After 5 to 8 min of carbogen breathing, the average oxygen tension increase in tumor tissue was 4.6 +/- 1.3 mm Hg, which is in agreement with an increase of the oxyhemoglobin concentration in tumor blood (Delta[O(2)Hb] = 9. 2 +/- 3 microM). However, simultaneously the TBP was reduced, the bioenergetic status was diminished, and pH was decreased. As 100% O(2) breathing alone did not result in a detectable increase of oxyhemoglobin in tumor blood, the increase of the tumor oxygenation by carbogen appears to be mediated by its CO(2) content. This component may cause a nutrient-limited decrease of oxidative energy metabolism, indirectly via a steal-effect and/or by inhibition of the glycolytic rate resulting from tissue acidification. Magn Reson Med 42:490-499, 1999.
van der Sanden
B P
BP
Department of Radiology, University of Nijmegen, Nijmegen, The Netherlands. B.vanderSanden@Rdiag.AZN.NL
Heerschap
A
A
Hoofd
L
L
Simonetti
A W
AW
Nicolay
K
K
van der Toorn
A
A
Colier
W N
WN
van der Kogel
A J
AJ
D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000097:blood; D003287:Contrast Media; D005461:Fluorine; D019786:Gadolinium DTPA; D005910:Glioma / Q000097:blood / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D010101:Oxygen Consumption; D019265:Spectroscopy, Near-Infrared; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured / Q000378:metabolism
D003287:Contrast Media; D006454:Hemoglobins; D002245:Carbon Dioxide; D005461:Fluorine; D019786:Gadolinium DTPA; D010100:Oxygen