The plasticity of posterior communicating artery influences on the outcome of white matter injury induced by chronic cerebral hypoperfusion in rats

This study was performed to identify which factors are involved in the development of white matter lesions induced by chronic cerebral hypoperfusion in rats.Male Wistar and Sprague-Dawley (SD) rats (250-270 g) were subjected to the permanent occlusion of bilateral common carotid arteries (BCCAO). The regional cerebral blood flow (rCBF) was measured by laser Doppler flowmetry and the plasticity of the posterior communicating artery (PcomA) was visualized by transcardiac perfusion of latex solution. For the histological examination, Klüver-Barrera staining was used to evaluate white matter damage.When compared with SD rats, Wistar rats showed lower rCBF after BCCAO, as well as thinner PcomAs. Moreover, 21 days after BCCAO, Wistar rats showed marked vacuolation of white matter in the optic tract, whereas SD rats had an almost intact optic tract.These results suggest that the plasticity of the PcomA and the reduction of rCBF in Wistar rats are important factors in the development of BCCAO-induced white matter lesions.