AGE DOES NOT ALTER PROTEIN-KINASE-C ISOZYMES MESSENGER-RNA EXPRESSIONIN RAT-BRAIN

Calcium and phospholipid dependent Protein kinase C (PKC) may play a r ole in memory function and pathogenesis of many neurodegenerative diso rders such as Alzheimer's disease (AD). Abnormal phosphorylation by PK C as well as reduced levels of PKC has been implicated in the neurodeg eneration associated with AD and aging. Recently, many subtypes of PKC isozymes have been identified by molecular biology techniques which a re expressed differentially in various regions of the brain. The reduc tion and alterations in the activities and distribution of these subty pes of PKC isozymes may be accountable for the decline of selective ne urons during aging. In order to investigate the role of PKC isozymes d uring aging, we examined the distribution of PKC-alpha, beta, and gamm a mRNA expressions between young (4 months) and old (25 months) rat br ains using in situ hybridization histochemistry. Our studies showed th at signals of three isoforms of PKC mRNA vary in cortical and hippocam pal regions. However, no change was detected in any of the PKC isoform s mRNA expressions in aged animals.