Health & Body - Adrenorphin: an opioid peptide active at multiple brain receptors

Adrenorphin is an endogenous opioid peptide formed from the enzymatic cleavage of proenkephalin A. It was initially identified in human phaeochromocytoma tumors arising from the adrenal medulla, before being confirmed in healthy human and bovine adrenal tissue as well as mammalian brains. Pharmacological research demonstrates that adrenorphin acts as a balanced agonist at both mu- and kappa-opioid receptors, while having no interaction with delta receptors. In addition to its potent pain-relieving properties, the molecule causes respiratory depression, illustrating how natural peptides modulate physiological processes.

Source: Wikipedia