Short term effect of nitrous oxide on methionine and S-adenosyl methionine concentrations.

Concentrations of methionine and S-adenosyl methionine (SAM) have been measured in various tissues of rats exposed to 50% nitrous oxide for periods up to 80 min, a time by which there is detectable interference with thymidine synthesis in bone marrow. There were no significant changes of either SAM or methionine in plasma, whole blood or brain. Hepatic SAM was unchanged, but there was a highly significant reduction in hepatic methionine, to 62% of control, after 80 min exposure to nitrous oxide.