[Influence of whole-body X-ray irradiation and 2, 4, 6-triethyleneimino- 1, 3, 5-triazine on the hypnotic effect of hexobarbital in mice (author's transl)].

The hypnotic effect of hexobarbital, measured in male NMRI-mice, was reduced during the first 24 hours after a unique or fractionated whole-body X-ray irradiation with 700 and 1400 R resp. 70 to 280 R and twelve hours after a unique intravenous injection of 16,0 mg tretamine per kilogram of body weight. Immediately after a unique injection of a high dose of tretamine and 24 hours after the last of four applications of 0,25 to 2,0 mg/kg which were repeated each after one day, the sleeping time after hexobarbital was prolonged. 24 hours after fractionated injection of tretamine (0,5 mg/kg each time), the concentration of hexobarbital in the brain showed a significant increase compared with the control animals. These results show that the decreased effect of hexobarbital in the early post-irradiation phase is based on pharmacodynamic processes while the increase of the effect produced by continued administration of tretamine can be explained by pharmaco-cinetic reasons.