*4.2.1.1 Nitrous oxide*

Nitrous oxide interferes with DNA, purine, and thymidylate synthesis, depressing neutrophil chemotaxis. Thus, it inhibits the formation of hematopoietic cells which may be important in tumor surveillance. Additionally, neutrophil function is depressed, and mononuclear cell production reduced. In studies with mice, it has been seen that nitrous oxide is associated with an acceleration in the development of lung and liver metastases, being the most powerful stimulator of liver metastases of the anesthetics studied [34].
