Effect of magnesium, MK-801 and combination of magnesium and MK-801 on blood-brain barrier permeability and brain edema after experimental traumatic diffuse brain injury.
OBJECTIVE
Glutamate antagonists are very attractive drugs in laboratory works to protect neural tissue against ischemia. In this work, the effects of magnesium, MK-801 and combination of magnesium and MK-801 on blood-brain barrier (BBB) and brain edema after experimentally induced traumatic brain injury are evaluated.


METHODS
A standard closed head injury was induced on the rats by a controlled impact device using a 450-g free falling mass from a height of 2 m onto a metallic disc fixed to the intact skull. One of the following was injected to animals intraperitoneally 30 minutes after injury: saline, magnesium, MK-801 and magnesium plus MK-801. To quantify the brain edema, the specific gravity of the brain tissue was determined. To demonstrate the alteration of the BBB permeability, Evans blue dye was used as a tracer.


RESULTS
In all treatment groups, the specific gravity of brain tissue values was significantly higher compared with the control group. Evans blue dye content in the brain tissue was significantly reduced in all three treatment groups with respect to the control group. There was no significant difference of effect between the groups of magnesium alone and MK-801 alone when compared with each other and when compared with their combination.


CONCLUSIONS
The present data demonstrate that treatment with magnesium, MK-801 and combination of magnesium and MK-801 can reduce formation of brain edema and can help restore BBB permeability after experimental diffuse brain injury.
Imer
Murat
M
Istanbul University, Istanbul, Turkey.
Omay
Bulent
B
Uzunkol
Ajlan
A
Erdem
Tulin
T
Sabanci
Pulat Akin
PA
Karasu
Aykut
A
Albayrak
Serdar Baki
SB
Sencer
Altay
A
Hepgul
Kemal
K
Kaya
Mehmet
M
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000503:physiopathology; D001834:Body Water / Q000187:drug effects / Q000502:physiology; D001929:Brain Edema / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D001930:Brain Injuries / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D020833:Diffuse Axonal Injury / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology* / Q000627:therapeutic use; D004338:Drug Combinations; D004357:Drug Synergism; D005070:Evans Blue / Q000493:pharmacokinetics; D016489:Head Injuries, Closed / Q000150:complications / Q000503:physiopathology; D007202:Indicators and Reagents / Q000493:pharmacokinetics; D017616:Magnesium Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D013046:Specific Gravity / Q000187:drug effects; D016896:Treatment Outcome
D004338:Drug Combinations; D007202:Indicators and Reagents; D017616:Magnesium Compounds; D018696:Neuroprotective Agents; D005070:Evans Blue; D016291:Dizocilpine Maleate