Emory Report homepage  

November 9, 2009
Sound Science
Progesterone: More than a sex hormone

Nearly 25 years ago, Donald Stein noticed a stark difference in how male and female rats faired after a brain injury. Female rats recovered more readily than males. Today that observation is paying off for patients suffering head trauma.

Stein, Asa G. Candler Professor of Emergency Medicine at Emory School of Medicine and director of the department’s Brain Research Laboratory, pioneered discoveries regarding the effect of progesterone following traumatic brain injury – first discovering the neuro-protective properties of progesterone in the laboratory.

“We noticed that where a female rat was in her estrus cycle at the time of injury determined how she faired afterwards,” says Stein. “Females that had high progesterone levels at the time of injury had a far better outcome than when they had a high estrogen level. So, we asked what would happen if we gave female rats progesterone when they were injured. Would it produce a benefit? And sure enough it did.”

Stein and his collaborators then asked what would happen if they gave male rats progesterone. “When we gave progesterone treatments to males, we found that the males did just as well as the females, and there was almost a complete elimination of brain swelling following trauma,” says Stein.

Working in collaboration with David Wright and Arthur Kellermann, professors of emergency medicine at Emory School of Medicine, and a group of post-docs and students, Stein began exploring the effect of progesterone in people with traumatic brain injury.

“Much to everyone’s surprise we got some very interesting and exciting results: mortality was reduced substantially and functional outcome was improved in these patients,” says Stein.

His Emory emergency medicine colleagues recently received a grant from the National Institutes of Health to expand their studies of progesterone to treat traumatic brain injury.

It’s not yet known for certain why progesterone has proven so effective in treating patients with traumatic brain injuries, but that is what Stein’s lab is investigating right now.