When the blood supply to a certain part of the brain is cut off-an event known as ischemic stroke-the neurons beyond the blocked blood supply are destroyed and if the condition is not treated within hours by clot-dissolving drugs, large areas of the brain are damaged irreparably.
One way in which neurons deprived of oxygen and blood are damaged is by a dramatic rise in the levels of calcium within the cells. Efforts are being made to develop medicines that prevent this calcium-induced damage, and scientists from Bristol Myers Squibb have developed a new class of drugs that may be effective against stroke by acting to prevent this calcium overload of cells (Nature Medicine, Vol. 7, No. 4, 01 Apr 2001).
Using a rat model of stroke, Valentin Gribkoff and colleagues tested the ability of BMS-204352 to protect against neuronal damage. Two hours after blocking a major artery to the brain, rats that were injected with BMS-204352 suffered significantly less brain damage than control animals. The compound is now undergoing safety tests in humans.
BMS-204352 works by opening what are known as large-conductance, calcium-activated potassium channels in the brain. These channels redress the balance of ions within neurons by ejecting potassium from cells which, in turn, prevents the further entry of calcium.
Dr. Valentin K. Gribkoff
Neuroscience Drug Discovery
Bristol-Myers Squibb Pharmaceutical Research Institute
Tel: +1 203 677 6620
Fax: +1 203 677 7569
(C) Nature Medicine press release.
Message posted by: Trevor M. D'Souza