Blood-Brain Barrier Breakdown after Embolic Stroke in Rats Occurs without Ultrastructural Evidence for Disrupting Tight Junctions
Figure 5
Ultrastructural evidence for transcellular, not paracellular leakage.
(A) Vessels in control areas on the contralateral hemisphere do not show signs of a transcellular, vesicle-mediated extravasation of FITC-albumin. (B–D) In contrast to alterations within the belts of tight junctions, ultrastructural examination regularly revealed signs for a transcellular leakage of the tracer. The endothelial cytoplasm exhibits a remarkable increase in vesicle density (white arrows) across the whole vascular circumference. Again, tight junctions (black arrow) are found to be intact. DAB grains are indicated by arrow heads. Control = contralateral hemisphere, E = endothelial cells; L = vascular lumen.