The role of CRF₂ receptors in corticotropin-releasing factor- and urocortin-induced anorexia

The experiments presented in this study were designed to assess corticotropin-releasing factor (CRF) receptor subtype mediation of CRF- and urocortin (UCN)-induced decrease in food intake. Male Sprague-Dawley rats were treated with antisense and sense oligonucleotides (ON) to CRF₂ receptor mRNAs for 36 h and then received an intracerebroventricular (i.c.v.) injection of CRF, UCN (3 μg) or saline. Antisense treatment significantly attenuated CRF- and UCN-induced suppression in food intake and HPA activation. Administration of CRF₁ receptor antagonist did not affect the decrease in food intake or activation of the HPA axis induced by ICV infusion of 3 μg CRF. The data suggest that down-regulation of CRF₂ receptors selectively attenuates CRF- and UCN-induced anorexia and hypothalamo- pituitary-adrenocortical activation in rats.