Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1762952 | Ultrasound in Medicine & Biology | 2006 | 11 Pages |
Abstract
Previously, activation of vesicular transport in the brain microvasculature was shown to be one of the mechanisms of focused ultrasound-induced blood-brain barrier (BBB) opening. In the present study, we aimed to estimate the rate of the transendothelial vesicular traffic after focused ultrasound sonication in the rabbit brain, using ultrastructural morphometry and horseradish peroxidase (HRP) as a tracer. In the capillaries, the mean endothelial pinocytotic densities (the number of HRP-containing vesicles per μm2 of the cell cytoplasm) were 0.9 and 1.05 vesicles/μm2 1 h after sonication with ultrasound frequencies of 0.69 and 0.26 MHz, respectively. In the arterioles, these densities were 1.63 and 2.43 vesicles/μm2, values 1.8 and 2.3 times higher. In control locations, the densities were 0.7 and 0.14 vesicles/μm2 for capillaries and arterioles, respectively. A small number of HRP-positive vesicles were observed in the venules. Focal delivery of HRP tracer was also observed in light microscopy. The results indicate that the precapillary microvessels play an important role in macromolecular transcytoplasmic traffic through the ultrasound-induced BBB modulation, which should be considered in the future development of trans-BBB drug delivery strategies. (E-mail: nsheikov@bwh.harvard.edu)
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Acoustics and Ultrasonics
Authors
Nickolai Sheikov, Nathan McDannold, Ferenc Jolesz, Yong-Zhi Zhang, Karen Tam, Kullervo Hynynen,