Cox B M, Gentleman S, Su T P, Goldstein A
Brain Res. 1976 Oct 15;115(2):285-96. doi: 10.1016/0006-8993(76)90513-8.
Pituitary peptides with opioid pharmacologic action (endorphins) can exist in several forms with different basicities and molecular weights from about 3000 to less than 1000 daltons. Partial purification yielded an endorphin at least 4 times more potent than normorphine and 16 times more potent than the endogenous brain pentapeptide methionine enkephalin. It is proposed that pituitary endorphin or a similar peptide in brain may be the precursor of brain enkephalin.
具有阿片样药理作用的垂体肽（内啡肽）可以以几种形式存在，它们具有不同的碱性和分子量，范围从约3000到小于1000道尔顿。部分纯化得到一种内啡肽，其效力至少是去甲吗啡的4倍，是内源性脑五肽甲硫氨酸脑啡肽的16倍。有人提出，垂体中的内啡肽或脑中类似的肽可能是脑啡肽的前体。
