Exercise has long been known as a driver of vascular expansion, but the mechanisms behind this are still poorly understood. A new study published in Cell Metabolism set out to investigate how exercise promotes the formation of thin blood capillaries in the muscles of healthy subjects. To do this, researchers studied the cells of the vascular wall (endothelial cells) in mice and cultured human cells.
As reported by Massage Therapy Canada, the researchers “discovered that there are two capillary endothelial cell types, which can be distinguished by the molecular marker ATF4. It turns out that cells with very little ATF4 are mainly found in the capillaries supplying the white muscle fibers, while cells with high levels of ATF4 primarily form part of the blood vessels close to red muscle fibers.”
The study demonstrated that exercise predominantly stimulates cell division of endothelial cells with high levels of ATF4 (those near red muscle fibers), leading to the formation of new capillaries. Exercise was not shown to elicit a direct response in cells with very little ATF4.
Visit https://doi.org/10.1016/j.cmet.2021.07.015 to view the full study.