Elephant Seals Harbor 'Silent Killer' in Their Blood that Could Treat Humans

Carbon monoxide is odorless, tasteless and deadly. It's known as the "silent killer" due to its risks at lethal concentrations. Now, though, researchers are learning a bit more about this gas by studying it in one of the world's best divers: the elephant seal.

Carbon monoxide (CO) is monitored in many homes with inexpensive detectors. In biological systems, like human bodies, CO is naturally produced as a byproduct of the breakdown of hemoglobin, which is a molecule responsible for transporting oxygen inside red blood cells. About one percent of the hemoglobin inside our bodies is linked with CO, though this can be elevated for chronic cigarette smokers.

Because CO is linked to how much oxygen can be transported in the blood the researchers decided to examine the gas in sea mammal divers. Elephant seals have the highest blood volume of any mammal and are known for their long, deep dives. They can conserve oxygen by shutting off blood flow to peripheral areas of their body and instead keep blood flowing to more vital organs. After studying these mammals, though, the researchers made some surprising discoveries.

"We found that the elephant seal is able to reach incredible depths, apparently with lots of carbon monoxide, so these results are helping us find answers for the rates at which you can expose organs and tissues to this gas," said Michael Tift, one of the researchers, in a news release. "The elephant seal is giving us the big picture of which concentrations of carbon monoxide might be the most beneficial."

In fact, the researchers found that CO is bound to 10 percent of the hemoglobin in adult elephant seals. While carbon monoxide can be deadly and toxic at specific levels, at lower levels it can be used to treat human illnesses. In fact, it has potential to be used for its protective and healing properties for organ transplants. Learning the amount which flows through elephant seals gives researchers a clearer picture about what safe levels might be.

"It is our hope that the elephant seal with be a useful model to explore the biological functions of carbon monoxide as well as to evaluate its potential as a therapeutic agent," said Paul Ponganis, one of the researchers, in a news release.

The findings are published in the Journal of Experimental Biology.