A new mechanism of blood redistribution has been uncovered by researchers at the University of Montreal Hospital Research Centre (CRCHUM). The in vivo study found that activated retinal areas received more blood than non-activated ones via a unique regulation system operated by pericytes. These cells have the ability to control the amount of blood passing through a single capillary simply by squeezing and releasing it.
“Using a microscopy technique, we showed that pericytes project very thin tubes, called inter-pericyte tunneling nanotubes, to communicate with other pericytes located in distant capillaries,” said Luis Alarcon-Martinez, a postdoctoral fellow at CRCHUM and one of the lead authors of the study. “Through these nanotubes, the pericytes can talk to each other to deliver blood where it is most needed.”
When capillaries lose their ability to shuttle blood where it is required – following an ischemic stroke, for example – cells begin to die. The findings suggest that microvascular deficits observed in neurodegenerative diseases, such as glaucoma and Alzheimer’s disease, could be the result of impaired blood distribution.
