Abstract
The anticonvulsant action of nitrous oxide and its time course were studied in rats. Bicuculline, a GABA-receptor antagonist, was administered intravenously at a rate of 0.2 mg·kg−1·min−1 during exposure to air (n=60) or 75% nitrous oxide in oxygen (n=80). The convulsant dose of bicuculline was determined. The rats were divided into subgroups according to the duration of exposure to air or nitrous oxide, from 0 to 120 min at 15 min intervals. Although the convulsant dose of bicuculline was consistent in the air group (1.03±0.06 mg·kg−1, mean ± SEM), it showed two peaks at 30- and 90 min exposures to nitrous oxide. The threshold dose in the nitrous oxide group was significantly higher than in the air group at only 15- and 30 min exposures (1.50±0.16, 2.15±0.25 mg·kg−1, respectively,P<0.05). We conclude that nitrous oxide has an anticonvulsant action against bicuculline-induced seizure, and that a cyclic nature exists in its action.
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Shingu, K., Osawa, M. & Mori, K. Cyclic alteration in the anticonvulsant effect of nitrous oxide in rats. J Anesth 4, 309–312 (1990). https://doi.org/10.1007/s0054000040309
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DOI: https://doi.org/10.1007/s0054000040309