Figure 1.

Elevation in cAMP cytosolic concentration increases PRL release from perfused pituitary lactotrophs. Cultured pituitary lactotrophs were perfused with extracellular solutions containing different concentrations of forskolin (Forsk), an adenyl cyclase activator, and dbcAMP. Samples were collected every minute and analyzed for either cAMP or PRL. a, Dose-dependent effect of forskolin on cAMP release in perfused lactotrophs. Gray represents the period of forskolin application. b, Dose-dependent effect of forskolin on PRL release from perfused lactotrophs. Gray represents the period of forskolin application. c, The effect of different concentrations of dbcAMP on the PRL release from perfused lactotrophs. The top x-axis represents the concentrations of applied dbcAMP. Shown are representative experiments from four independent experiments.