Effects of Daphnetin on Activities of Protein Kinase A and Protein Kinase C in Vitro / 中草药

Daphnetin, isolated from Daphne koreane Nakai, has been reported to dilate blood vesse ls, inhibit thrombosis and have antiinflammatory effect. In this study, type Ⅰ and type Ⅱ protcin kinase A partially purified from rat skeletal muscle and protein kinase C from rat brain were incubated with varying concentrations of daphnetin. Type Ⅱ protein kinase A was siguificantly inhibited by daphnetin at the concentration of 0.0056?mol/L, while type Ⅰ protein kinase A and protein kinasc C were inhibitcd at the concentrations of 5.6?mol／L and 56 ?mol/L, respectively. The results indicated that daphnetin might be used as a specific inhibitor of type Ⅱ protein kinase A