Differential effects of propranolol on vasoactive intestinal peptide-, and epinephrine-induced glycogenolysis in cultured liver cells.

When isolated rat liver cells were incubated in the presence of epinephrine and dopamine at concentrations ranging from 0.2 ug to 2.0 ug per ml, glycogenoloysis was maximally stimulated within 15 min. The combined addition to incubation medium showed that somatostatin did not inhibit the stimulated glycogenolysis induced by epinephrine and dopamine. On the other hand, the combined addition to the incubation medium showed that propranolol inhibited the stimulated glycogenolysis induced by epinephrine, while propranolol did not inhibit the stimulated glycogenolysis induced by vasoactive intestinal peptide. These results suggest that the receptor site for vasoactive intestinal peptide may be different from that of epinephrine.