In paraquat ingestion where the toxicant is transported in the blkoodstream and poisons the Type IIpneumatocytes in the lungs turning them into scar tissue, ,NO used as a pulmonary vasodilator in low doses which are beneficia li nincreasing oxygenation of the blood without the need for higher inspired oxygen fractions. We have used it successfully (rarely) in cases of paraquat ingestion. The paraquat travels through theions bloodstream and poisons type II pneiumatocytes by a reactive species generation process, which once started continues even after all the paraquat had been excreted. Treatment with increasing fractions of supplemental oxygen actally accelerates this process. NO pulmonary vasodilationcan accomplish the same thing without elevated inspried oxygen fractions. The one drawback has been concern about generating methemoglobinemia. Methempoglobin cannot bind and transport oxygen to the body. This has usually been studied in dogs, which have been shown in older French literature to be 10 or more times suscible to methemoglobin induction than humans.

So this is yet another example of a medicinal use of a compound that is beneficial in low doses but toxic at higher ones.

However, this IS NOT an argument that environmental pollution is "good" for you. Apples and ranges comparison. Regardless if you hanker to embrace the theory that global climate change is the result totally of human activity (not supported by much good scientific data), we can all agree that having clean air to breath, clean water to drink,a safe and adequate food supply, etc., etc. are good things in themselves.

Alan

Alan H. Hall, MD.

Medical Toxicologist