In a study bound to raise hope in Multiple Sclerosis (MS) patients, researchers have reported significant changes in MS symptoms of mice, administered with pregnancy hormone prolactin.
Multiple Sclerosis causes the body's immune system to attack the protective coating around immune system This leads to damage that cannot be repaired.
The hormone prolactin secreted during pregnancy and lactation, stimulates breast development and milk production and has been tested in humans for other reasons.
The researchers from the University of Calgary's Hotckiss Brain Institute, destroyed myelin around the nerve cells in the mice, as seen in MS. Two weeks later, the pregnant mice had twice as much new myelin as the other mice. When the scientists injected prolactin into the non-pregnant mice, their myelin similarly was repaired.
Results were published in the Journal of Neuroscience.
Says Dr. Samuel Weiss director of the Hotckiss Brain Institute,"It's early to be confident that prolactin will definitely work with people, but prolactin represents the first example of any molecule, in this case a naturally occurring molecule, that can actually boost the repair of myelin."
While current MS treatments are designed to prevent new damage in patients in earlier stages of the disease, there is nothing to repair myelin that has already been destroyed.
"This may give us some ways to now focus on protecting the brain, as opposed to giving therapies that just reduce the attacks," said Dr. Jock Murray, a professor of medicine at Dalhousie University and founding director of its multiple sclerosis research unit.
The Calgary team has begun further tests with prolactin on mice to determine whether there are any drawbacks associated with the hormone and whether it can be administered with existing MS medications that target the immune system. It is not known what impact the hormone will have on men.
Says Weiss: "If the next series of studies looks promising, we may be prepared to study prolactin in (human) trials."