Capillaries have a unique method of ejecting debris, such as blood clots, cholesterol or calcium plaque, that blocks supply of vital nutrients to brain cells. The facts have been revealed by a new study at Northwestern University’s (NU) Feinberg School of Medicine (FSM).
The capillaries spit out the blockage by growing a membrane that envelopes the obstruction and then pushes it out of the blood vessel. Scientists also found this critical process is 30 to 50 per cent slower in an ageing brain and likely results in the death of more capillaries. “The slowdown may be a factor in age-related cognitive decline and may also explain why elderly patients who get strokes do not recover as well as younger patients,” said Jaime Grutzendler, study co-author and principal investigator and assistant professor of Neurology and Physiology at FSM.
Scientists have long understood how large blood vessels clear blockages: blood pressure pushes against the clot and may eventually break it down and flush it away, or clot busting enzymes rush to the scene to dissolve a blockage. But very little was previously known about how capillaries clear blockages. The study first demonstrated that enzymes and blood pressure aren’t efficient at clearing capillary clots.
Those mechanisms only work half the time and only when blood clots are involved, not other types of debris, particularly cholesterol, which is difficult to dissolve. —IANS