Primary hepatocytes were isolated from 12-week-old male WT ( Prom1+/+) and KO (Prom1-/-) mice, serum-starved for 16 hours and stimulated with isoprenaline. (H) The nuclear localization of p-CREB after isoprenaline stimulation (10 μM) for 10 minutes was determined by immunofluorescence staining. Scale bar, 20 μm. 