Thymidine and methionine syntheses in pregnant rats exposed to nitrous oxide.

Abstract

The dose-dependent effects of nitrous oxide on thymidine and methionine syntheses were investigated in pregnant rats. Female Sprague-Dawley rats were exposed on day 9 of gestation to 0.75%, 7.5%, or 75% nitrous oxide for 24 h. Immediately and 72 h after exposure, a deoxyuridine-suppression test was performed on maternal bone marrow and a methionine synthetase assay was performed on maternal liver to assess thymidine and methionine syntheses, respectively. Inhibition of thymidine synthesis was seen after exposure to 7.5% and 75%, but not after 0.75%, nitrous oxide. Recovery was complete 72 h after exposure. Methionine synthetase activity was abolished at all concentrations of nitrous oxide tested and did not return to control values 72 h after exposure. Fetal weight and gross appearance were not affected by exposure to nitrous oxide; however, the observed decrease in thymidine and methionine syntheses after nitrous oxide exposure may account for its teratogenic effects.

• Authors: J M Baden, S A Rice, M Serra, M Kelley, R Mazze
• Journal: Anesthesia and analgesia (Anesth Analg) Vol. 62 Issue 8 Pg. 738-41 (Aug 1983) ISSN: 0003-2999 [Print] United States
• PMID: 6869860 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Methionine
• 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase
• Nitrous Oxide
• Thymidine
• Deoxyuridine

Topics

• 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase (metabolism)
• Animals
• Deoxyuridine
• Female
• Methionine (biosynthesis)
• Nitrous Oxide (pharmacology)
• Pregnancy
• Pregnancy, Animal (drug effects)
• Rats
• Rats, Inbred Strains
• Thymidine (biosynthesis)