Corticotropin-releasing factor (CRF) at a dose of 3 micrograms administered intracerebroventricularly (i.c.v.) elicited increases in noradrenaline (NA) release, which was assessed by intracerebral microdialysis in the anterior hypothalamus of conscious rats. These increases persisted until 140 min after infusion of CRF. These results indicate that CRF enhances NA release in the hypothalamus, an effect which may underlie the 'stress-like' properties of CRF.