Adrenergic stimulation of RBC P-5′-N activity. RBCs (cytokrit 4%) from day 11 were incubated for 16 hours at 37°C in the absence and presence of 10 μmol/L NE, 10 μmol/L propranolol (prop), and 35 μmol/L actinomycin D (actD). Data are given as the mean value and SD from five experiments in each case. (***P< .001, **P < .01).