1973年实验证实哺乳动物脑组织中有阿片受体,对吗啡能起作用,从而引起探索吗啡受体及其内源性配体的热潮。1975年从猪脑中分离出甲硫氨酸脑啡肽(M-enkephalin;甲啡肽)和亮氨酸脑啡肽(L-enkephalin;亮啡肽)。这些肽都是β-趋脂素(β-LP H;B-Lipotropin)的氨基酸残基61—65片段。以后又有人陆续从猪的下丘脑抽提物中分离出α、β、γ和δ内啡肽(Endorphin),分别相当于β-LPH的61—76、61—91、61—77和61—87氨基酸片段。最近又有人发现前原强啡肽(Preprodynorphin)衍生 Experiments in 1973 confirmed that mammalian opioid receptors in the brain tissue, morphine can play a role, which led to explore the morphine receptor and its endogenous ligand craze. In 1975, methionine enkephalin (M-enkephalin) and leu-enkephalin (Leu-enkephalin) were isolated from porcine brain. These peptides are all 61-65 amino acid residues of β-LPotropin (β-LP H; B-Lipotropin). Later, some people gradually isolated α, β, γ and δ endorphins from the hypothalamic extracts of pigs, corresponding to 61-76, 61-91, 61-77 and 61-77 of β-LPH, 87 amino acid fragment. Recently, it was found that preprodynorphin was derived