[Distribution and activity of pyridoxal kinase in human brain during ontogenesis]

The activity of pyridoxal kinase was sharply increased in whole brain tissue of human, embryos and fetuses within 6-11 weeks of development. In brain stem the maximal values of the enzyme activity was observed at early stages of prenatal development of fetuses. The activity of pyridoxal kinase was increased in cerebral cortex and in the limbic system up to complete maturation of fetuses. It correlated with the fetus age within 14-40 weeks of development as calculated per 1 g of tissue wight or 1 mg of protein. The enzyme is distributed evenly in brain of newborns, babies and adult people. Its activity in grey cortex substance is higher, than in white one. There are 2-10-fold individual fluctuations of pyridoxal kinase activity in brain of people without CNS pathology. In newborns, having prolonged hypoxy at prenatal period, the enzyme activity was on the average by 70-80% lower at different brain parts than in newborns which had no primary asphyxia. A low pyridoxal kinase activity (not more than 1-5% as compared with its normal level) was observed in different brain parts of a child affected by focal gliosis and epilepsy.