Tight junction disruption of blood-brain barrier in white matter lesions in chronic hypertensive rats.

Tight junctions (TJs) are the most important structure of the blood-brain barrier (BBB). Studies have shown that triggering of white matter lesions (WMLs) may be related to a BBB dysfunction, but rarely have studies observed the progressive changes in TJs longitudinally. In our present study, the ultrastructure of TJs was observed using a transmission electron microscope in Stroke-prone Renalvascular Hypertensive Rats. Western blotting was used to detect TJ-related proteins zonula occludens-1 and occludin. The results showed that in Stroke-prone Renalvascular Hypertensive Rats, the severity of WMLs increased gradually. TJs was destroyed gradually 8 weeks after hypertension. The levels of zonula occludens-1 and occludin also decreased gradually. These data suggested that long-term hypertension may contribute toward the gradual disruption of TJs of BBB and induce WMLs in chronic hypertensive rats.