What is hydrogen gas and why are we studying it?
The therapy we are proposing to test is a gas that can be breathed in through the lungs or administered through the ECMO circuit called hydrogen gas. Hydrogen gas is the lightest and most abundant molecule in the universe. It doesn’t have a smell or a color if you are around it. You may have heard of hydrogen as an environmentally-friendly source of fuels. In fact, there are tiny amounts of hydrogen in the air we breathe too.
At the concentrations we will use in this research trial, hydrogen is considered safe and well tolerated. Hydrogen has also been consumed as hydrogen water or tablets.
The structure of hydrogen is very simple – it’s just two hydrogen atoms, each one made up of a single proton, neutron and electron, covalently bonded together. And the name hydrogen tells us something very important about it – hydro means water, and gen means generating. From the very first experiences with hydrogen its reactivity with oxygen to form water has been recognized.
Fortunately, hydrogen’s reactivity with oxygen is actually critical to its action. Here’s why. When the heart or lungs fail in their job – as happens in a cardiac arrest – cells begin to use oxygen in a toxic way. Specifically, modified oxygen species – like superoxide, peroxide, and hydroxyl radical are generated. These oxygen species are highly reactive and directly damage critical components of cells, like DNA and the lipid membranes that coat our cells. These actions directly cause cell death. When hydrogen is present in the blood, a landmark research study found that hydrogen effectively behaves as a sponge, absorbing these toxic species and decreasing the damage that occurs from a lack of oxygen.