Urocortin II is a neuropeptide hormone and member of the corticotropin-releasing factor (CRF) family which includes mammalian CRF , urocortin , urocortin III , frog sauvagine, and piscine urotensin I.

Mouse urocortin II shares 34 and 42% sequence homology with rat CRF and urocortin . It is expressed in mouse paraventricular, supraoptic, and arcuate nuclei of the hypothalamus, the locus coeruleus, and in motor nuclei of the brainstem and spinal ventral horn. Urocortin II selectively binds to CRF1 over CRF2 receptors (Kis = 0.66 and >100 nM, respectively) and induces cAMP production in CHO cells expressing CRF2 (EC50 = 0.14 nM).

In vivo, urocortin II suppresses nighttime food intake by 35% in rats when administered intracerebroventricularly at a dose of 1 μg. Urocortin II (0.1 and 0.5 μg, i.c.v) stimulates fecal pellet output, increases distal colonic transit, and inhibits gastric emptying in mice.2