Metabolism of nitrous oxide by human and rat intestinal contents.
Hong-K; Trudell-JR; O'Neil-JR; Cohen-EN
Anesthesiology 1980 Jan; 52(1):16-19
The reduction of nitrous-oxide (10024972) (N2O) to nitrogen (7727379) (N2) by intestinal contents was studied. Sprague-Dawley- rats were treated with antibiotics and sacrificed. Intestines and contents were removed from treated and untreated rats. Homogenates of the contents of small and large intestines of rats, and of human large intestinal contents were prepared. Homogenates were also prepared from the intestinal wall of rats. Homogenates were degassed and treated with isotopically labeled N2O (15N20) and incubated. Homogenates were also treated with 5, 10, and 20 percent oxygen (2). The amount of 15N15N produced by homogenates indicated that intestinal contents from rats and humans metabolize N20. Metabolism was greatly inhibited by 02 at 10 and 20 percent, and partially inhibited at 5 percent O2. Intestinal wall homogenates had a very low rate of metabolism. The authors conclude that intestinal contents possess high N20 reductase activity under anaerobic conditions and moderate activity under low 02 tension normally found in intestines. They note that free radical intermediates may be produced from the metabolism of N20 to N2 which may be important to the etiology of carcinogenesis.
NIOSH-Publication; NIOSH-Grant; Nitrogen-oxides; Laboratory-animals; Gastrointestinal-system; Biochemistry; Metabolism
Anesthesia Stanford University 300 Pasteur Drive Stanford, Calif 94305
Stanford University, Stanford, California