Primary hepatocytes were isolated from 12-week-old male WT ( Prom1+/+) and KO (Prom1-/-) mice, serum-starved for 16 hours and stimulated with isoprenaline. (J) The cAMP concentration after isoprenaline stimulation (10 μM) for 10 minutes was determined using the cAMP assay kit in the presence of 10 μM IBMX (n = 3/group). 