Having trouble breathing through your mouth? Hang on in there! Anal oxygen administration may soon be a reality. "Researchers are planning oxygen enemas," writes The Economist.
As far as is known, no land vertebrate can perform this trick. But, in a paper just published in Cell, Takebe Takanori of the Cincinnati Children's Hospital, in Ohio, describes how terrestrial animals might, with a bit of assistance, be enabled to so. So far, Dr Takabe and his colleagues have turned mice, rats and pigs into bottom breathers. If they can extend the trick to people, it could offer an alternative to tracheal intubation as a means of keeping those with breathing difficulties alive.
Takebe and his collaborators provide evidence for intestinal breathing in rats, mice, and pigs. First, they designed an intestinal gas ventilation system to administer pure oxygen through the rectum of mice. They showed that without the system, no mice survived 11 minutes of extremely low-oxygen conditions. With intestinal gas ventilation, more oxygen reached the heart, and 75% of mice survived 50 minutes of normally lethal low-oxygen conditions.
Because the intestinal gas ventilation system requires abrasion of the intestinal muscosa, it is unlikely to be clinically feasible, especially in severely ill patients—so the researchers also developed a liquid-based alternative using oxygenated perfluorochemicals. These chemicals have already been shown clinically to be biocompatible and safe in humans.