Research to investigate new drug for Parkinsons disease

Aug 2 2005

Researchers at the University of Sydney have received a grant to investigate the potential of a new drug to treat the abnormal posture and balance that affects people with Parkinson's disease ultimately confining them to a wheelchair.

Dr Jasmine Henderson and Professor Michael Kassiou from the University of Sydney’s Department of Pharmacology have received a $49,500 grant from the Rotary Club of Liverpool West and the Australian Rotary Health Research Fund.

Parkinson's disease is a degenerative disorder which causes muscular shaking and stiffness, slowness of movements and difficulties with posture and balance. It affects over 40,000 Australians and the number appears to be rising.

At present there is no known cause of the disease but research worldwide is investigating possible causes including exposure to pesticides, toxins and chemicals, head trauma, and genetic factors.

Dr Henderson says that Parkinson’s disease is caused by damage to the part of the brain, the substantia nigra, which makes a chemical messenger called dopamine.

“Dopamine assists in coordinating movement,” said Dr Henderson. “A lack of dopamine producing cells causes symptoms such as muscle stiffness and slowness.”

“The main drug currently used to treat Parkinson’s disease, levodopa, improves these symptoms but doesn’t help other symptoms of the disease such as abnormal posture and balance.

“Many people also experience loss of effectiveness of their symptoms and side effects such as disabling twisting movements called dyskinesias after using levodopa and most people don’t respond too well to long term use of the drug,” said Dr Henderson.

Recent studies of the brains of Parkinson disease patients by Dr Henderson and her colleagues at the Prince of Wales Medical Research Institute found that another part of the brain, a small region in the thalamus, also degenerates. This part of the brain uses glutamate, not dopamine, as its chemical messenger.

“Until this discovery,” said Dr Henderson, “most of the major symptoms of Parkinson’s disease had been attributed to a lack of dopamine in the brain.”

Dr Henderson and Professor Kassiou have found that destroying glutamate producing cells in the thalamus of animals causes changes in the animals’ postures and other behaviours, suggesting that damage to the thalamus may contribute to postural changes similar to the symptoms seen in patients with Parkinson’s disease.

“We are using the funding from Rotary to test a new drug, known as Compound GR-1, which acts on glutamate to see if it improves symptoms such as postural changes,” said Dr Henderson.

“We are predicting that a combination of levodopa and this drug will be more effective in treating some symptoms of Parkinson’s than levodopa alone,” she said.

Rotary Club of Liverpool West representative Greg Peel said that when the club was discussing what area of medical research they might fund, it seemed everyone in the club knew someone who was, or had been, affected by Parkinson’s disease.

“It’s a pity that Parkinson’s disease doesn’t have a higher profile with so many people directly and indirectly affected by it,” said Mr Peel.

“We hope the $60,000 we’ve raised to fund research into the disease will lead to some practical improvements in the lives of sufferers, as well as more public awareness about the disease,” he said.

Parkinson’s Awareness Week will run from September 4 to 10.

The Australian Rotary Health Research Fund (ARHRF) is one of the largest independent medical research funds in Australia. Since its establishment 25 years ago the ARHRF has committed more than $10 million to Australian medical research.