Fig. 1.

Whole brain irradiation (WBI) induces persistent endothelial dysfunction in the cerebral circulation. Laser Doppler probe measurements were utilized to assess changes in cerebral blood flow (CBF) in the cerebral cortex of mice following topical perfusion of the endothelium-dependent vasodilator agents acetylcholine (A) and ATP (B) at 3 months post-WBI. Bar graphs depict summary data. Importantly, both acetylcholine and ATP-induced CBF responses in the somatosensory cortex were significantly reduced in WBI-treated mice compared to control animals, indicative of impaired endothelial function persisting at 3 months post-irradiation. Data presented are mean ± S.E.M. (n = 8 for each data point). *P < 0.05 vs. control