Abstract

1. Pentothal and seconal are rapidly destroyed by the intact mouse. Under similar conditions a much smaller degree of degradation of phenobarbital occurs, while there was no evidence of degradation of barbital.

2. Rabbit liver slices degrade pentothal, seconal, amytal, pentobarbital, and to a slight extent alurate. Liver brei shows somewhat less activity while homogenized liver shows no activity.

3. Pentothal is the only barbiturate tested which is degraded by kidney slices.

4. Muscle and brain brei do not destroy any of the barbiturates tested with the exception of slight destruction of pentothal by brain brei.

5. The evidence presented indicates that the kidney breaks down only the malonyl thiourea ring while the liver breaks down both the malonyl thiourea and malonyl urea rings. The speed with which the rings are attacked varies with the nature of the side chains.