Regulation of pantothenate kinase from various tissues of the rat

The relative tissue activities of pantothenate kinase range from 1 to 5 nmol . min-1 . g-1 wet wt for heart, brain, kidney, and liver. The enzyme partially purified from each tissue is inhibited by CoA, but there is a 10-fold greater potency of inhibition of the heart enzyme compared to those from the other tissues. With the heart and liver enzyme, this difference in potency of CoA inhibition may be a reflection of the differing cytosolic CoA concentrations in these tissues. L-Carnitine specifically reversed the inhibition of each enzyme by CoA. It is concluded that L-carnitine may be a regulator of CoA synthesis in each tissue.