The abundance of mRNAs for pyruvate dehydrogenase kinase isoenzymes in brain regions of young and aged rats

The abundance of mRNAs for pyruvate dehydrogenase kinase (PDK) isoenzymes i n four brain regions of young (10 wk) and aged (50 wk) rats was investigate d by reverse transcription-polymerase chain reaction (RT-PCR). The mRNAs fo r PDK1,2, and 4 were detected in all the regions examined, The level of PDK 2 mRNA was the most abundant among the isoenzymes in all the brain regions when judged from the PCR cycles. The level of PDK1 mRNA was relatively high in cerebellum and cerebral cortex compared to medulla oblongata and hippoc ampus. Aging decreased the levels of mRNAs for PDK1 and 2 in cerebellum and increased the PDK2 mRNA in hippocampus and cerebral cortex. The level of P DK4 mRNA was not affected by aging. These results provide the first evidenc e suggesting that there is the regional difference in the abundance of mRNA s for PDK isoenzymes in rat brain and that the levels of mRNAs for the isoe nzymes were affected by aging. (C) 2000 Elsevier Science Inc. All rights re served.