Featured Research

from universities, journals, and other organizations

Drug Slows And May Halt Parkinson's Disease

June 12, 2007
Northwestern University
Researchers have discovered a drug that slows -- and may even halt -- the progression of Parkinson's disease. The drug rejuvenates aging dopamine cells, whose death in the brain causes the symptoms of this devastating and widespread disease.

Northwestern University researchers have discovered a drug that slows -- and may even halt -- the progression of Parkinson's disease. The drug rejuvenates aging dopamine cells, whose death in the brain causes the symptoms of this devastating and widespread disease.

Related Articles

D. James Surmeier, the Nathan Smith Davis Professor and chair of physiology at Northwestern University's Feinberg School of Medicine, and his team of researchers have found that isradipine, a drug widely used for hypertension and stroke, restores stressed-out dopamine neurons to their vigorous younger selves. The study is described in a feature article in the international journal Nature, which will be published on-line June 10.

Dopamine is a critical chemical messenger in the brain that affects a person's ability to direct his movements. In Parkinson's disease, the neurons that release dopamine die, causing movement to become more and more difficult.

Ultimately, a person loses the ability to walk, talk or pick up a glass of water. The illness is the second most common neurodegenenerative disease in the country, affecting about 1 million people. The incidence of Parkinson's disease increases with age, soaring after age 60.

"Our hope is that this drug will protect dopamine neurons, so that if you began taking it early enough, you won't get Parkinson's disease, even if you were at risk. " said Surmeier, who heads the Morris K. Udall Center of Excellence for Parkinson's Disease Research at Northwestern. "It would be like taking a baby aspirin everyday to protect your heart."

Isradipine may also significantly benefit people who already have Parkinson's disease. In animal models of the disease, Surmeier's team found the drug protected dopamine neurons from toxins that would normally kill them by restoring the neurons to a younger state in which they are less vulnerable.

The principal therapy for Parkinson's disease patients currently is L-DOPA, which is converted in the brain to dopamine. Although L-DOPA relieves many symptoms of the disease in its early stages, the drug becomes less effective over time. As the disease progresses, higher doses of L-DOPA are required to help patients, leading to unwanted side-effects that include involuntary movements. The hope is that by slowing the death of dopamine neurons, isradipine could significantly extend the time in which L-DOPA works effectively.

"If we could double or triple the therapeutic window for L-DOPA, it would be a huge advance," Surmeier said.

The work by Surmeier's group is particularly exciting because nothing is known to prevent or slow the progression of Parkinson's disease.

"There has not been a major advance in the pharmacological management of Parkinson's disease for 30 years," Surmeier said.

Surmeier, who has researched Parkinson's disease for 20 years, had long been frustrated because it wasn't known how or why dopamine cells die in the disease. "It didn't seem like we were making much progress in spite of intense study on several fronts," he said.

Because he's a physiologist, Surmeier decided to investigate whether the electrical activity of dopamine neurons might provide a clue to their vulnerability. All neurons in the brain use electrical signals to do their job, much like digital computers.

First, Surmeier observed that dopamine neurons are non-stop workers called pacemakers. They generate regular electrical signals seven days a week, 24 hours a day, just like pacemaker cells in the heart. This was already known. But then he probed more deeply and discovered something very strange about these dopamine neurons.

Most pacemaking neurons use sodium ions (like those found in table salt) to produce electrical signals. But Surmeier found that adult dopamine neurons use calcium instead.

Sodium is a mild mannered ion that does its job without causing a whit of trouble to the cell. Calcium ions, however, are wild and rambunctious. Remember when Marlon Brando rode into town with his motorcycle gang in "The Wild One"" Those guys were like calcium ions.

"The reliance upon calcium was a red flag to us," Surmeier said. Calcium ions need to be chaperoned by the cell almost as soon as they enter to keep them from causing trouble, he noted. The cell has to sequester them or keep pumping them out. This takes a lot of energy.

"It's a little like having a room full of two year olds you have to watch like a hawk so they don't get into trouble," Surmeier said. "That's really going to stress you." With three boys under age eleven, he can relate to the stressed dopamine neuron.

Surmeier theorized that the non-stop stress on the dopamine neurons explains why they are more vulnerable to toxins and die at a more rapid rate as we age.

But these findings still didn't offer him a new therapy.

Then, serendipity struck when he was working on a different problem. He discovered that young dopamine neurons and adult ones have an entirely different way of operating.

When the neurons are young, Surmeier found they actually use sodium ions to do their work. But as the neurons age, they become more and more dependent on the troublesome calcium and stop using sodium. This calcium dependence -- and the stress it causes the neurons --is what makes them more vulnerable to death.

What would happen, Surmeier wondered, if he simply blocked the calcium's route into the adult neuron cells?  Would the neurons revert to their youthful behavior and start using sodium again?

"The cells had put away their old childhood tools in the closet. The question was if we stopped them from behaving like adults would they go into the closet and get them out again"" Surmeier asked. "Sure enough, they did."

When he gave the mice isradipine, it blocked the calcium from entering the dopamine neuron. At first, the dopamine neurons became silent. But within a few hours, they had reverted to their childhood ways, once again using sodium to get their work done.

"This lowers the cells' stress level and makes them much more resistant to any other insult that's going to come along down the road. They start acting like they're youngsters again," Surmeier said.

The next step will be launching a clinical study.

"This animal study suggests that calcium channel blockers, drugs currently used to reduce blood pressure, might someday be used to slow the steady progression of Parkinson's disease," said Walter J. Koroshetz, M.D., deputy director of the NINDS.

Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.

Cite This Page:

Northwestern University. "Drug Slows And May Halt Parkinson's Disease." ScienceDaily. ScienceDaily, 12 June 2007. <www.sciencedaily.com/releases/2007/06/070610175143.htm>.
Northwestern University. (2007, June 12). Drug Slows And May Halt Parkinson's Disease. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2007/06/070610175143.htm
Northwestern University. "Drug Slows And May Halt Parkinson's Disease." ScienceDaily. www.sciencedaily.com/releases/2007/06/070610175143.htm (accessed October 25, 2014).

Share This

More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins