What is L-dopa?

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What is L-dopa?

By Chelsie Vandaveer

http://www.killerplants.com/plants-that-changed-history/20030902.asp

 

September 2, 2003

 

Suggested Reading:

 

The Windsor bean is one of the many varieties of the fava bean

(Vicia faba Linnaeus). As a favorite dish, this bean was cultivated

in the garden of Fritz Hoffmann, owner of Hoffmann-La Roche Limited.

 

In 1913 a Roche biochemist, Marcus Guggenheim analyzed Windsor

beans from Hoffmann's garden. He isolated dihydroxyphenylalanine or

dopa. The amino acid was thought biologically inert and little

attention was paid to the discovery. ( " Therapy for Idiopathic

Parkinson's Disease, Irena Rektorova, MD, European Parkinson's

Disease Association, 2002)

 

 

 

Almost a century earlier, James Parkinson published an article

concerning his observations of three patients suffering from palsy.

Parkinson was the first to carefully describe the symptoms of the

men, all over age 50. His 1817 An Essay on the Shaking Palsy was so

astute that today the disorder carries his name, Parkinson's

disease. ( " The Story of Shaking Palsy " , History of PD, Mayo Clinic)

 

Dopa has two forms: dextrorotary or D-dopa and levorotary or L-dopa.

 

The molecules are stereoisomers or mirror-images of each other.

 

In 1938, animal and human studies found an enzyme that converted L-

dopa into dopamine.

 

But it would not be discovered until 1960 that people with

Parkinson's disease had severe dopamine deficits.

 

Research discovered the body converts the amino acid tyrosine into L-

dopa; L-dopa is then converted into dopamine.

 

Without the neurotransmitter dopamine to serve a damping effect on

neural transmissions, muscles become tense and tremble.

 

Even though lack of dopamine is the problem, it cannot be given as a

treatment.

 

Dopamine cannot cross the barrier between the bloodstream and the

brain, but L-dopa can.

 

The enzyme L-dopa decarboxylase changes L-dopa into dopamine in the

basal ganglia of the brain.

 

Since 1966, L-dopa has been the standard treatment to alleviate the

symptoms of Parkinson's, but it is not a cure. As the disease

progresses, L-dopa eventually fails and causes a host of adverse

side-effects. ( " Dopamine " , William S. Messer, Jr., Medicinal and

Biological Chemistry, University of Toledo, 2000)

 

 

 

 

The Mayo Clinic has an excellent website about Parkinson's disease.

To learn more about a disease that affects more than a million

Americans, :

 

http://www.mayo.edu/fpd/home/intro.htm

 

Use links at top of page to navigate the site.

 

 

 

Suggested Reading:

Why does favism exist? Plants that Changed History - October 14, 2003

 

What is favism? Plants that Changed History - October 7, 2003

 

Why did ladies use bean poultices? Herbal Folklore - September 8,

2003

What is L-dopa? Plants that Changed History - September 2, 2003

 

What is a fava bean? Weird Plants - September 4, 2003

 

How did we get so many varieties from the common bean? Weird Plants -

September 20, 2001

 

How is a toxin found in the kidney bean useful? Herbal Folklore -

September 17, 2001