[Pharmacological studies on Y-8894. (IV). Ameliorative effect on a cerebral energy metabolism disorder induced by KCN].

The amelioration of energy metabolic disturbance in cerebral anoxia is valuable for the treatment of various cerebral ischemic diseases and insufficiency. In this study, the effect of Y-8894 on the cerebral energy metabolism was investigated using a KCN-induced cerebral anoxia model with mice. The intravenous injection of a lethal dose of KCN (2.5 mg/kg) induced rapid and marked decreases of brain glucose, phosphocreatine and ATP contents, with a remarkable enhancement of lactate and AMP levels, indicating a severe disorder of the cerebral energy metabolism. This phenomenon was also shown by an irreversible deterioration of the energy charge potential (ECP), an index of the cerebral energy state. The treatment with Y-8894 (30 mg/kg, i.p.) remarkably ameliorated this KCN-induced energy metabolic disturbance: markedly reducing the changes in brain phosphocreatine, glucose and lactate contents, while keeping ATP, AMP and ECP at nearly their normal levels. In addition, these changes in the Y-8894 treated group recovered promptly to normal, whereas those in the control group were irreversible. In normal mice, Y-8894 induced a significant increase in the cerebral glucose content without affecting either the cerebral glycolytic metabolism or the energy state. The present findings suggest that Y-8894 has an ameliorative effect on the cerebral energy metabolic disturbance, and this effect likely plays an important role in the improvement of amnesia and other neurological deficits related to cerebral anoxia.