Researchers began by studying Ethiopian runners, a population that tends to dominate the world's marathons. These athletes come from a high-altitude country, and thus have bodies that are better able to adapt to lower levels of oxygen.
"This is the first demonstration that a gene involved in high altitude adaption is critical in protecting cardiac function in moderate to severe hypoxia at sea level," said lead author Gabriel Haddad, chair of the department of pediatrics at the University of California at San Diego.
All about oxygen regulation
The scientists completed whole-genome sequencing on a sample of the population, and discovered that the endothelin receptor type B gene, which produces the endothelin receptor type B protein (EDNRB), might be a candidate for how the body regulates how much oxygen gets around the body.
This protein, scientists think, helps blood vessels dilate and helps cells multiply when the body is developing. In this study, researchers found a direct link between EDNRB expression and the way the heart operates.
They then took lab mice and compared those with normal levels of the EDNRB protein with mice that had low levels of EDNRB. Those mice with lower levels of the protein were better able to adjust in low-oxygen environments, even when the amount of oxygen in the air was less than five percent, lower than the amount of oxygen at the top of Mount Everest.
"Lowering EDNRB does wonders for mice when environmental oxygen levels are low, leading us to conclude that the EDNRB gene plays a key role in human adaption to low oxygen and high altitude," Haddad said in a statement.
"The idea that reducing the expression of functional EDNRB to help cells and tissues endure extreme hypoxia is appealing and may lead to novel therapies for cardiac failure in the near future,” said Tsering Stobdan, PhD, assistant project scientist in Haddad's lab and first author of the study, in a statement.
The next step, UC San Deigo said, is testing therapeutic drugs that inhibit the EDNRB protein.