Substance P stimulates translocation of protein kinase C in brain microvessels

The action of substance P on protein kinase C in cerebral microvessels, isolated from bovine, was investigated. We found that in untreated microvessels 85% of the total activity was localized to the cytosolic fraction. Substance P caused a shift of activity to the membrane fraction, accompanied by a loss of activity in the cytosolic fraction. This effect resulted in dose-dependence and it was evident after 5 min treatment. These data suggest that substance P may be involved in the regulation of processes underlying protein phosphorylation in the blood-brain barrier.