Drug Averts Parkinson's Disease Brain Damage
Mirapex May Protect Brain Cells From Parkinson's Disease
Oct. 13, 2004 -- Mirapex, a drug used to treat symptoms of Parkinson's disease, might also help guard the brain against the disease's damage.
The finding, published in the Oct. 11 issue of the online journal BMC Biology, is based on lab tests with mice given Parkinson's disease.
Previous research suggested that Mirapex might block brain damage caused by Parkinson's disease. However, earlier animal studies used massive doses that wouldn't be safe for people.
Now, researchers report success in animal experiments with a Mirapex dose that humans with Parkinson's disease could tolerate.
Parkinson's disease affects nerve cells in an area of the brain called the substantia nigra. When healthy, these cells produce dopamine, a brain chemical used to help control the body's movements.
Parkinson's disease breaks down those cells, making dopamine levels drop and scrambling the brain's movement signals.
The disease usually strikes later in life, after age 50, although some people are diagnosed in their 30s and 40s. Patients may experience problems including tremors, muscle stiffness, and slowed motion.
The cause of Parkinson's disease is not known, and there is no cure. However, symptoms can be treated with drugs including Mirapex, which imitates dopamine's effects.
The new study was conducted by researchers including Jeffrey Joyce of the Thomas H. Christopher Center for Parkinson's Disease Research at the Sun Health Research Institute in Sun City, Ariz.
Can Mirapex Stop Parkinson's Disease?
Joyce and colleagues studied 10 mice.
For five days, they treated the mice with a daily shot of Mirapex or a placebo. Mirapex, which is available in pill form for humans, was given in a dose similar to what people would take, say the researchers.
On the fourth and fifth days, some of the mice also received two daily injections of a chemical called MPTP, which destroys brain cells in the substantia nigra and leads to Parkinson's disease. The rest of the mice received a placebo.
Mirapex had a powerful protective effect.
It blocked all nerve cell loss in the mice given MPTP, safeguarding their brains from Parkinson's-like symptoms.
"These results suggest that protection occurs at clinically suitable doses of [Mirapex]," write the researchers.
Previous studies used Mirapex doses that were 10-30 times higher, according to a news release.
Further work is needed to explore Mirapex's possible protective effects in humans.