Radiation effects on the blood-brain barrier

Selective vascular irradiation enables the critical examination of the vasculature and its role in the onset of late radiation effects. It is a novel approach to expose the endothelial cells to much higher levels of ionizing radiation relative to normal cells by utilizing the boron neutron capture reaction. When boron-containing compounds are restricted to the lumen of the blood vessel, the resulting high-LET alpha and lithium particles cannot deposit their energy in the normal cells beyond the vasculature after the target is exposed to thermal neutrons. This allows for a 2- to 3-fold increase in the calculated dose to the endothelial cells. However, this technique has been criticized because there is no direct evidence that the endothelial cells receive an absorbed dose from the selective vascular irradiation. The objective of this work is to provide corroborating experimental evidence that selective vascular irradiation physically damages the endothelial cells. An established assay utilizing blood-brain barrier disruption was adopted to quantify the radiation damage to the endothelial cells in female BALB/C mice, 8-12 weeks of age. A dye that attaches to the plasma proteins in the blood and that is ordinarily kept out of the brain by the blood-brain barrier is injected into the blood supply before the irradiation, and following irradiation, damage to the vasculature will result in disruption of the blood-brain barrier that allows blood stained with the dye to enter the brain. After sacrificing, the blood in the vessel lumen is cleared by performing a trans-cardiac perfusion, and the brain is homogenized and prepared for analysis. The absorbance of the resulting supernatant of each brain sample is measured with a spectrophotometer at the optimal wavelength of the dye.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Nuclear Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Raabe, Rebecca L

Advisor dc:contributor.advisor

• Jeffrey A. Coderre.

• Nuclear Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/44779

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/44779