Effects of chronic exposure to nitrous oxide on methionine synthase activity
| Autor: | I. Chanarin, N.M. Sharer, John F. Nunn, J.P. Royston |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Chronic exposure
Male medicine.medical_specialty Time Factors Nitrous Oxide 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase chemistry.chemical_compound Internal medicine Medicine Animals Pooled data Methionine synthase activity chemistry.chemical_classification Dose-Response Relationship Drug business.industry Rats Inbred Strains Nitrous oxide Methyltransferases Rats Dose–response relationship Anesthesiology and Pain Medicine Enzyme Endocrinology chemistry business Statistical evidence |
| Zdroj: | British journal of anaesthesia. 55(8) |
| ISSN: | 0007-0912 |
| Popis: | Hepatic methionine synthase activity has been determined in rats continuously exposed (24h day−1 and 7 day week−1) to concentrations of nitrous oxide ranging from 500 to 50000 p.p.m. for periods ranging from 24 h to 28 days. The inactivation of this enzyme was dependent upon both time and concentration of nitrous oxide exposure, but there was no statistical evidence that exposure continuing beyond 48 h increased the effect. However, the dose-response curve for 24 h was significantly different from the curve for pooled data from exposures lasting 2–28 days. These latter data indicated no significant effect with 450 p.p.m. and an ED 50 of 5400 p.p.m. Significant inhibition was detected at 1000 p. p.m. These results suggest that the limit of exposure of 25 p.p.m. recommended by the American National Institute of Occupational Safety & Health may be unduly restrictive. |
| Databáze: | OpenAIRE |
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