It is remarkable how often we find that a treatment for one problem may turn out to help something completely different.
Parkinson’s disease is caused by a loss of dopamine neurons in specific circuits in the brain. Dopamine has a great many actions, but I these particular circuits it is involved in the control of movement. Once it starts, the process usually continues on inexorably. The mystery has been why the neurons die in the first place.
There is a very promising article that was published online today in the journal Nature.
Investigators from the Department of Physiology in the Feinberg School of Medicine at Northwestern University in Chicago and the Department of Cellular and Molecular Pharmacology at the Chicago Medical School, Rosalind Franklin University of Medicine and Science have looked at a medicine that is usually used for treating hypertension, and found that it may protect dopaminergic neurons.
Their studies have suggested that the dopaminergic neurons involved are unusually reliant on a type of calcium channel that maintains their rhythmic activity. If the pacemaker is damaged, the neurons become more vulnerable to stressors such as neurotoxins. As we age, calcium ions begin to enter the neurons and change their behavior. They showed that mice that had been engineered to develop a progressive Parkinson's-type disease did not become ill when their condition was treated with the calcium channel blocker israpidine. Their dopamine neurons appeared to revert back to their original, youthful form.
It is much to early to think about using isradipine for treatment. We do not, for example, know whether it works in humans and we have any idea how much of the drug would be needed. But this research does suggest a whole new line of research and possibilities for treatment.
That is exciting, though when I read about research like this I always wish that researchers did not use animals in their experiments. But since the animals have made the sacrifice to help us, we need to acknowledge their help.