title: Blood-brain barrier permeability during shortlasting intravascular hyperosmolality.
abstract: Blood-brain barrier permeability for 24Na+ and 36Cl- ions and for 3HOH was studied during isoosmolality and during shortlasting intravascular hyperosmolality in twenty-five patients using the double indicatir single injection method. Hyperosmolality was induced by a rapid injection into the internal carotid artery of 8 ml of one of the following hypertonic solutions: 5% saline, 25% mannitol or a contrast medium of the metrizoat group (Isopaque-amine 280). The extractions of the small sodium and chloride ions remained unchanged and essentially zero indicating that 'opening' of the blood-brain barrier did not occur. The blood-brain barrier permeability to water remained unchanged during hyperosmolality, but the extraction of 3HOH increased when mannitol and especially when Isopaque-amine 280 was used as hypertonic agent corresponding to the lower water concentration in these solutions.
mesh_terms: D001812:Blood-Brain Barrier; D001834:Body Water / Q000378:metabolism*; D002713:Chlorine / Q000378:metabolism*; D003287:Contrast Media; D006801:Humans; D006982:Hypertonic Solutions; D008353:Mannitol / Q000008:administration & dosage; D009994:Osmolar Concentration; D010539:Permeability; D012462:Saline Solution, Hypertonic; D012964:Sodium / Q000378:metabolism*
chemical_list: D003287:Contrast Media; D006982:Hypertonic Solutions; D012462:Saline Solution, Hypertonic; D008353:Mannitol; D002713:Chlorine; D012964:Sodium