Forskolin stimulates cAMP production and the onset of the functional differentiation in the fetal rat thyroid in vitro.

Forskolin, a diterpen stimulating the adenylcyclase induces in vitro an accumulation of cAMP in thyroid glands explanted from 17 day-old rat fetuses. Thyroid glands from 15 day-old fetuses exposed to forskolin exhibit, within 24 hr, an active folliculogenesis and 125I fixation in follicular cavities. The results indicate that cAMP probably activates the onset of both morphological and physiological maturation in the fetal rat thyroid.