IMPAIRED GENE-TRANSCRIPTION AND NUCLEAR-PROTEIN KINASE-C ACTIVATION IN THE BRAIN AND LIVER OF AGED RATS

The expression of the hsp70 and c-fos genes and the activation of nucl ear protein kinase C (PKC) were studied in young and aged whole rats u nder heat-shock conditions. The induction of hsp70 and c-fos genes by heat shock were decreased several fold in the brain as well as in the liver of senescent animals. Nuclear run-off transcription assay indica ted that this age-related impairment could be attributed to a block at the level of transcription. Nuclear PKC activation by heat shock was not apparent in old animals. Nuclear PKC involvement in the repression of transcription during senescence is postulated.