Endogenous ligands of opiate receptors.
From brain and from pituitary tissue of vertebrates several peptides - with molecular weights between 500 and 3500 daltons - have been isolated, which behave like opiates in opiate receptor binding assays, in isolated tissue preparations and in the intact animal.
D000818:Animals; D001923:Brain Chemistry; D008024:Ligands; D009842:Oligopeptides; D010455:Peptides / Q000032:analysis*; D010902:Pituitary Gland / Q000032:analysis; D011957:Receptors, Opioid / Q000378:metabolism*
D008024:Ligands; D009842:Oligopeptides; D010455:Peptides; D011957:Receptors, Opioid