REGULATION OF PROTEIN-KINASE-C ACTIVITY IN CEREBRAL MICROVESSELS

Regulation of protein kinase C (PKC)-mediated responses may occur by i nhibition of PKC-dependent phosphorylation or by dephosphorylation of targets by specific phosphatases. Mechanisms for the regulation of PKC were examined in isolated cerebral microvessels and compared to those in brain. The data demonstrated that inhibitors of phosphorylation ar e responsible for the regulation in brain microvessels while dephospho rylation by protein phosphatases accounts for a substantial portion of the regulation of the PKC response in brain. In addition, the inhibit ory activity apparently increases with age. These results suggest that the control of PKC may be cell-type specific and developmentally regu lated.