Hi Kate,

I.V. Mannitol was and is still used to temporary "prevent" BBB disruption in large (or so called malignant) hemisphereic stroke or in other neurocritical diseases with BBB break-down and brain swelling (long-term outcome changes were disappointing). It works only temporary to decrease clinical makers like ICP most likely by its onkotic pressure (so in Neuro-ICUs it is sometimes life-saving). Therefore, I.V. injections may be critical for your purposes to disrupt the BBB. However, Paracelsus is calling: It all about the dose.

I.P. can not work at all, because mannitol as a large molecule should not enter the circulation that good. It is rather made for not crossing endothelial barriers. 

To disrupt BBB with mannitol you may need rapid changes of mannitol and thereby the onkotic pressure in the brain cirulation, then mannitol have a paradox effect leading to an "opening" of BBB. That means I.A. mannitol injection or as a compromise I.V. injection is the only way to bring it to the brain circulation in a rapid and higher dose.

I hope these information will help a bit for planing your experiments.

Best Bert

_______________________________________________

Bert Bosche, MD/PhD

Specialist in Neurology, Neurocritical Care,

Neurosurgical Research Fellow - Post-doc Scientist

in the Laboratory of Prof. Dr. R. Loch Macdonald

Division of Neurosurgery

St. Michael's Hospital and Li Ka Shing Knowledge Institute

209 Victoria St., Room 517

Toronto, Ontario, Canada M5C 1N8

E-mail: [email protected]

Phone: +1 416-864-6060 ext. 77641

Mobil: +1 647-204-4757 or +49 173-7076734