Gene Identified as Critical to Low-Oxygen Tolerance

Researchers have identified a gene that helps people tolerate low-oxygen conditions, according to a study published Monday, opening the way for new treatments for heart failure and related conditions.

"This is the first demonstration that a gene involved in high altitude adaptation 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.

The researchers identified a gene they believe may help Ethiopians who have lived at high altitudes, where oxygen levels are relatively low, for thousands of years. That gene, EDNRB, encodes a protein that is believed to help blood vessels dilate.

For this study, researchers monitored the relative performance under hypoxic conditions of mice with normal levels of EDNRB and those with low levels. Mice with low levels of EDNRB were better able to maintain normal heart rhythms, blood pressure and oxygen flow to vital organs, even when oxygen was below levels found at the summit 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 adaptation to low oxygen and high altitude," Haddad said.

He said this advance could help in the search for better therapies for those living at sea level who suffer from heart attacks, strokes and other low oxygen-related diseases.

The study appeared in the journal Proceedings of the National Academy of Sciences (PNAS).