CRF, bovine is a potent agonist of CRF receptor, and displaces [I-Tyr]ovine CRF with a Ki of 3.52 nM. CRF shows pEC50s of 11.16, 8.53 and 8.70 for human CRF1, human CRF2 and rat CRF2α. CRF is released from hypothalamic-pituitary-adrenal (HPA) axis induced by stress, and leads to production of glucocorticoids which down regulate immune responses. CRF also has proinflammatory effects. CRF affects brain microvessel endothelial cells (BMEC) structure or function, CRF (100 nM) significantly increases cAMP in BMEC.