Effect of Combined Administration of Estrogen and Progesterone on Brain Edema and Neurological Outcome after Traumatic Brain Injury in Female Rats

Many studies have shown uncontrolled brain edema to be the cause of disabilities and deaths following head trauma. Current data also suggests that a single administration of estrogen or progesterone can have neuroprotective effects on brain injury. In this study we investigated the combined effect of estrogen and progesterone on brain edema and neurological outcomes following traumatic brain injury (TBI) in female rats.

This interventional-�experimental study was performed on 8 groups of female rats as follows: 1- control, 2-Sham, 3-Ovarectomized trauma (TBI+OVX) 4-Vehicle 5-Physiologic dose of estrogen + physiologic dose of progesterone (E1+P1), 6- physiologic dose of estrogen+pharmacologic dose of progesterone (E1+P2) 7-Pharmacologic dose of estrogen+physiologic dose of progesterone (E2+P1) and 8-Pharmacologic dose of estrogen+pharmacologic dose of progesterone (E2+P2). Hormones were injected i.p, half an hour after diffuse traumatic brain injury through marmarou model to 2 week old ovarectomized rats. Brain edema (via brain water content), blood-brain barrier permeability (via extravascular evans blue dye) and neurological outcome (via veterinary coma scale) were measured in this animals.

The results showed significance decreases of 2.68% and 2.88% in water content in group 8 compared to the vehicle group and group 6 respectively and a significant decrease of 2.29% in water content in group 5 compared to group 6. Evans blue level showed significant decreases of 14.7% and 21.1% in groups 6 and 7 compared to the vehicle group. Neurological scores showed a significant increases of 2.5 and 2 in group 5 compared to the vehicle group and group 3, 1 hour after TBI respectively a significant increase was seen in all groups compared to group 3 at 4 and 24 hours after TBI. Scores showed a significant increase of 1.2 in groups 7 and 8 compared to the vehicle group at 24 hours following the TBI.

Based on these results, it can be concluded that combined administration of estrogen and progesterone have benefical effects on both the reduction of brain edema and the neurological outcomes, the improvement depending on what dose of estrogen is administered with progesterone.