Mountain climbers and patients with serious breathing difficulties could both benefit from a discovery by scientists in the US.

Researchers at the University of Pittsburgh have found that injections of a chemical solution into the bloodstream may significantly boost the capacity of the lungs.

The discovery could enable mountain climbers to cope with low oxygen levels at high altitude while also helping patients with lung problems or difficulty breathing.

A lot more work has to be done but obviously it is a very encouraging start

Dr Mark Britton, British Lung Foundation

The finding, which is based on experiments on rats, was presented at the annual meeting of the American Society for Artificial Internal Organs in New York.

Dr Marina Kameneva and colleagues injected a small concentration of a solution of blood-soluble drag-reducing polymers (DRPs) into the tail veins of one group of rats. A saline solution was injected into a second group.

High altitude

Both sets of rats were subjected to atmospheric pressure corresponding to an altitude of 25,000ft - 4,000ft lower than the peak of Everest.

Overall, 40% of rats died. However, all of those injected with DRPs survived.

Dr Kameneva said the solution was found to boost the delivery of oxygen around the body even at altitudes where oxygen levels would be low.

She said: "The use of DRPs increases oxygen delivery to tissue and organs and leads to enhanced oxygen utilisation, even at low concentrations."

Dr Kameneva said the discovery could have benefits for a variety of people.

"This could have a positive impact for patients who experience respiratory distress or failure or in conditions of significantly lowered oxygen supply."

Dr Mark Britton, chairman of the British Lung Foundation, described the research as very encouraging.

"A lot more work has to be done but obviously it is a very encouraging start."

He added: "One of the problems we have had is there has been no method of delivering oxygen to tissues in an enhanced way apart from through the lungs.

"This appears to be a way of maximising and utilising oxygen which may be in short supply due to disease in the lungs.

"Therefore, one of the issues is when clinically the situation becomes critical the only way at the moment is to put someone on a ventilator.

"But perhaps using this new polymer one could bide time whilst hopefully other therapies have time to have an effect."