The effects of magnesium sulfate on blood-brain barrier disruption caused by intracarotid injection of hyperosmolar mannitol in rats.
The study was performed to evaluate whether magnesium sulfate could alter the degree of disruption of the blood-brain barrier (BBB) caused by hyperosmotic mannitol. Wistar adult female rats were infused with 25% mannitol into the left internal carotid artery. Each animal received intraperitoneally a 300 mg/kg loading dose of magnesium sulfate, dissolved in 0.9% saline, followed by a further 100 mg/kg dose. In the other group, intracarotid infusion of magnesium sulfate was performed at a dose of 150 mg/kg 10 min before mannitol administration. Evans blue (EB) dye was used as a marker of BBB disruption. The measured serum glucose and magnesium levels increased after mannitol and/or magnesium administration when compared with their initial values before treatment (P < 0.01). Water content of the left hemisphere was significantly increased by hyperosmotic mannitol (P < 0.01). The increased water content in the mannitol-perfused hemisphere was significantly decreased by magnesium treatment (P < 0.05). The content of EB dye in the mannitol-perfused hemisphere markedly increased when compared with the right hemisphere of the same brain (P < 0.01). The EB dye content in the mannitol-perfused hemisphere following both intraperitoneal and intraarterial administration of magnesium decreased when compared with mannitol alone (P < 0.01). We conclude that although magnesium sulfate administration by both intracarotid arterial and intraperitoneal routes attenuates BBB disruption caused by hyperosmolar mannitol, particularly intraperitoneal route of magnesium sulfate administration may provide a useful strategy to limit the transient osmotic opening of the BBB.
Kaya
Mehmet
M
Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Capa-34 390 Istanbul, Turkey. mehkaya@istanbul.edu.tr
Gulturk
Sefa
S
Elmas
Imdat
I
Kalayci
Rivaze
R
Arican
Nadir
N
Kocyildiz
Zuhal Celebi
ZC
Kucuk
Mutlu
M
Yorulmaz
Hatice
H
Sivas
Ahmet
A
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects*; D001929:Brain Edema / Q000139:chemically induced / Q000517:prevention & control*; D002339:Carotid Arteries; D004234:Diuretics, Osmotic / Q000633:toxicity*; D005070:Evans Blue; D005260:Female; D007261:Infusions, Intra-Arterial; D007274:Injections, Intraperitoneal; D008278:Magnesium Sulfate / Q000494:pharmacology*; D008353:Mannitol / Q000633:toxicity*; D009994:Osmolar Concentration; D051381:Rats; D017208:Rats, Wistar
D004234:Diuretics, Osmotic; D008353:Mannitol; D005070:Evans Blue; D008278:Magnesium Sulfate