[Effect of chronic hyperphenylalaninemia and hypoxia on the effectiveness of the alpha-ketoglutarate shunt in the brain].

The effects of hypoxia and chronic hyperphenylalaninaemia (HPA) on the intensity of the alpha-oxoglutarate shunt in rat brain after injection of [5-14C]glutamate were investigated. The reaction of reducing carboxylation of alpha-oxoglutarate was shown to be the rate-limiting step for the whole pathway. The deceleration of this reaction under chronic HPA or, conversely, its increase under short-term heavy hypoxia led to a corresponding decrease or increase of fatty acid synthesis in the brain with [5-14C]glutamate as a radioactive precursor.