Effect of ODQ and milrinone on cAMP degradation. RBC from day-11 chick embryos were incubated for 2 hours at 37°C with 10 μmol/L NE, washed, and resuspended in fresh buffer (control) or buffer with 30 μmol/L ODQ or 20 μmol/L milrinone. Cyclic AMP measurements started with addition of ODQ or milrinone and were performed over 60 minutes. Data are the mean values and SD from 3 experiments.