Influence of Age and Dietary Stress on Hexobarbital Activity in Mice. ∗

Conclusion

1. Mice maintained on an 8% casein diet are capable of synthesizing drug metabolizing enzymes during the period of rapid body growth. 2. Mice maintained on this diet exhibit a prolonged hexobarbital sleeping time at all periods after one week of experimental feeding. 3. The increased sleeping time seen during the earlier period of experimental feeding may result from a less active TPNH generating system than is present in controls. 4. The increased sleeping time seen during the fourth to fifth week on the 8% casein diet probably results from an actual decrease in the level of drug metabolizing enzyme and in cofactor level, as well as from a lower level of body fat in these animals.