Cytogenetic evaluation of spermatogonial cells in the rat following long-term inhalation exposure to nitrous oxide plus halothane. Final report.
NIOSH 1976 Nov; :1-24
The mutagenicity of chronic nitrous-oxide (10024972) (N2O) plus halothane (151677) inhalation was investigated. Male Sprague-Dawley- rats were exposed for 7 hours per day, 5 days per week for a total of 52 weeks to normal air or air containing 50 parts per million (ppm) of N2O plus 1ppm of halothane, or 500ppm of N2O plus 10ppm of halothane. After 12 weeks of exposure, the rats were removed for a 21 day mating period and were then returned to the exposure chambers. After the 52 week exposure period, surviving rats were killed and spermatogonial cells were analyzed for chromosome aberrations. Survival rates and terminal body weights were similar in all three groups. The incidence of chromatid gaps was similar between the groups, but chromatid breaks associated with fragments were significantly increased in the high exposure group. Chromosomal breaks were not induced by N2O and halothane exposure. The mean number of cells with chromosomal markers, as well as the mean number of markers, was increased in both exposure groups. The incidence of markers was dose related. Also increased in the exposed groups were cells with multiple types of aberrations. The authors conclude that long term N2O plus halothane inhalation causes chromosomal damage to spermatogonial cells of rats.
NIOSH-Contract; Contract-099-74-0046; Mutagens; Animal-studies; Anesthetics; Reproductive-effects; Chromosome-damage; Dose-response; Cellular-reactions
Final Contract Report
NTIS Accession No.
National Institute for Occupational Safety and Health
Hazleton Laboratories America, Inc.