Does calmodulin participate as an intermediate in the process of glycogenolysis in rat submandibular gland?

A role of calmodulin in the process of the glycogenolysis induced by adrenaline was investigated in rat submandibular gland. When the slice was incubated in the Ca2+-free medium, the adrenaline-induced glycogenolysis was significantly inhibited. Moreover, the inhibition of glycogenolysis induced in the Ca2+-free medium was further enhanced by addition of 2 mM EGTA. Chlorpromazine, trifluoperazine and W-7, calmodulin antagonists, had no effect on the glycogenolysis induced by adrenaline. These results suggest that the adrenaline-induced glycogenolysis is dependent on the presence of Ca2+ and that calmodulin does not participate in the process of glycogenolysis in rat submandibular gland.