Biochemical aspects of experimental barbital dependence II: Effect on glycometabolism.

A single injection of barbital increased glycogen, while it decreased glucose and glucose-6-phosphate levels in the rat brain. In long barbital dosing (36 days), however, the metabolite level of carbohydrate was almost recovered to the non-treated level. At the later stage of withdrawal (24-48 hr), all metabolites examined except lactate decreased. Only lactate increased remarkably. The effect of barbital dosing and withdrawal was almost same in the three portions, i.e., the cerebral cortex, brain stem, and cerebellum. Barbital depresses the central glycometabolism, and at the dependent stage (long term barbital dosing, 36 days or more), metabolism was almost same as the control. At the later period of withdrawal, it appeared that lactate was increased because of the hypoxic condition caused by stroke. In conclusion, carbohydrate metabolism can probably serve as a sensitive measure for the development of barbital dependence and the onset of withdrawal.