Fig. 3.

Dose-dependent stimulation of ghrelin secretion by adrenergic but not cholinergic or GABA agonists in PG-1 cells. On day 0, PG-1 cells were set up in medium A with 10% FBS. On day 2, octanoate was added to the medium at a final concentration of 50 μM. On day 3, cells were centrifuged, resuspended in serum-free medium B with 50 μM octanoate, aliquoted into 24-well plates (5 × 10⁴ cells per well), and treated with varying concentrations of the indicated compound. After incubation at 37 °C for 6 h, the medium and cells from each well were harvested for measurement of ghrelin (A and B) and des-acyl ghrelin (C and D). Each value is the average of duplicate incubations. □, none.