Stimulation of hypothalamic β-endorphin and dynorphin release by corticotropin-releasing factor (in vitro)

Corticotropin-releasing factor (CRF) at doses of 10⁻¹²–10⁻⁸ M significantly stimulated the release of β-endorphin and dynorphin from superfused rat hypothalamic slices. These effects were shown to be mediated by the CRF receptor since they were antagonized by the CRF receptor antagonist α-helical CRF_9–41 (10⁻⁶ M). The two opioid peptides showed different time courses of response and in the case of β-endorphin, an attenuation of the response upon continued exposure to CRF was observed.