Effects of ATP synthesis inhibitors, temperature, 8-bromo c-AMP, and calcium omission on release of corticotropin releasing factor from superfused rat hypothalami.

The release of immunoreactive corticotropin-releasing factor (I-CRF) was studied in vitro using a hypothalamic superfusion system. Omission of calcium, or inclusion of ATP synthesis inhibitors in the medium significantly reduced the rates of basal and K+-induced I-CRF release. Reducing the incubation temperature of the hypothalami to 4 degrees C caused a reversible inhibition of basal I-CRF release. I-CRF release was stimulated in a dose-dependent fashion by 8-bromo c-AMP. Those results suggest that the in vitro release of CRF is energy-dependent and may involve a calcium and c-AMP-mediated mechanism.