Relation of time of administration of drugs to their acute toxicity to experimental animals
Hata, T.; Okage, T.; Miyake, Y.; Kita, T.
Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica 71(1): 29-37
1975
ISSN/ISBN: 0015-5691 PMID: 1171811 Document Number: 95100
The circadian rhythms of acute toxicity of N-methyl D-aspartic acid, picrotoxin, pentetrazol, strychnine, chlorpromazine and Na-methylhexabital in dd-mice were investigated. The drugs were injected into mice on the hour at 2, 6, 10, 14, 18 or 22 in one day, after which the cumulative mortalities were calculated for 72 hours. Regarding central stimulants, the mortality of mice injected at 22 (o'clock) was lowest, and when injections were given at 2, 10 or 18 (o'clock), the mortality was higher than at any other time. On the other hand, regarding central depressants, the mortality was lowest at 10, and highest at 14 or at 18 o'clock. Thus, the administration time of central stimulants showing the lowest mortality was shifted about 12 hours in comparison with central depressants. As compared to the central depressants, the mortality rate as the result of central stimulants showed a great contrast when injected at 10 o'clock.