Leaky blood vessels that cannot prevent spread of toxins to the spinal cord may boost rapid progression of amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease, a study by researchers at University of Rochester Medical Centre has found.
Lou Gehrig's or ALS is a progressive and fatal, neurodegenerative disease caused by the degeneration of motor neurons, the nerve cells in the central nervous system that control voluntary muscle movement thereby causing muscle weakness.
"We believe these changes contribute to or possibly initiate the onset of ALS," Nature quoted Dr Berislav Zlokovic lead author, of the University of Rochester Medical Centre, as saying.
"It's clear that these changes occur before the loss of neurons, and it's well known that the types of changes we are seeing certainly injure or kill these types of cells, which are extremely sensitive to their biochemical environment," he added.
The researchers conducted their study over mice mutant in a gene for superoxide dismutase 1 (SOD-1). SOD-1 plays a crucial role in keeping cells safe from damaging molecules known as free radicals in healthy people and mice.
They found that the mice intended to get ALS displayed a breakdown in the natural barrier between the blood and the spinal cord long before nerve cells appear sick or die, thereby permitting toxic substances to flood into the spinal cord and directly influence neurons.
Researchers also found that a SOD-1 mutation interrupted chief building blocks in the barrier.
With the weakened barrier the neurons were exposed directly to biochemical by-products of haemoglobin that formed reactive oxygen molecules that injure neurons, even diminutive hemorrhages appeared on the spinal column.
"The vascular system is crucial to health - it's how oxygen and other nutrients are delivered to cells, and how toxins are removed," said Zlokovic
"Any damage to the vascular system is a serious threat to the organism. It's clear now that the vascular system is certainly involved in the development of ALS," he added.
The study is published in the April issue of Nature Neuroscience.