Histologically Neuroprotective Effect of MgSO4 after Moderate Diffuse Axonal Injury in Rats

Shim, Yu Shik; Park, Chong Oon; Hyun, Dong Keun; Ha, Yoon; Park, Hyeon Sun; Park, Hyung Chun

Abstract

OBJECTIVE
Previous studies have shown that blood-ionized magnesium levels decline, associated with the development of histological changes(apoptosis), after traumatic brain injury. Therefore, we have a hypothesis that early magnesium salt treatment may be improving posttraumatic apoptotic change.
METHODS
Thirty two anesthetized adult Sprague-Dawley rats were injured with a Marmarou's weight-drop device and bloodionized magnesium was checked, prior to and following magnesium administration(MgSO4 750µmol/kg. IM). The temporal pattern of apoptosis in rat brain after moderate diffuse axonal injury(mDAI) was characterized using TUNEL histochemistry.
RESULTS
After MgSO4 injection at 30 min. posttrauma, animals demonstrated an elevated blood-ionized magnesium concentration reaching a maximum of 2.57±0.03mg/dL at 2.5 hours after drug administration and apoptotic index was significantly declined by about 45%(54.8±1.7, 51.5±3.2 at 12, 24 h in control group, 24.8±2.6, 20.5±1.4 at 12, 24 h in treated group, p<0.05).
CONCLUSIONS
These findings suggest that early treatment with MgSO4 is very effective in histological findings following experimental traumatic brain injury in the rat. Clinically, we suspect that an increase in blood-ionized magnesium concentration with administration of magnesium salt may be associated with improvement in neurological and functional outcome.