Pregnancy Hormone May Ease Multiple Sclerosis

THURSDAY, Feb. 22, 2007 (HealthDay News) -- A hormone produced during pregnancy may benefit multiple sclerosis patients, a Canadian study finds.

Multiple sclerosis (MS) affects about 2.5 million people worldwide. It occurs when the body's immune system attacks myelin, which insulates nerve cells and plays a critical role in the transmission of messages from cell to cell. Reductions in myelin lead to a progressive loss of sensation and movement in MS patients.

Interestingly, MS goes into remission when women get pregnant. Since prolactin is a hormone that is produced during pregnancy, the researchers sought to determine if prolactin was the reason behind MS remission during pregnancy.

"It was thought that during pregnancy, [women's] immune systems no longer destroyed the myelin," study author Samuel Weiss, of the Hotchkiss Brain Institute of the University of Calgary, said in a prepared statement. "But no previous study has tested whether pregnancy actually results in the production of new myelin, which may explain improvement of symptoms," he said.

In the study, published in the Feb. 21 issue of the Journal of Neuroscience, researchers counted hundreds of cells in the brains and spinal cords of mice. They compared the cells in pregnant versus virgin female mice of the same age.

The team found that the pregnant mice had twice as many myelin-producing cells and continued to generate new ones during pregnancy. Even after giving birth, the once-pregnant mice had 50 percent more myelin coating their nerve cells.

The researchers also found that prolactin mimicked the effects of pregnancy, increasing both myelin production and repair in the mice.

If future research confirms the benefits of prolactin in animal models of MS, Weiss says the hormone will be ready for testing as a treatment for people with MS.

More information

The National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.