Do endorphin residues of beta lipotropin in hormone reinforce reproductive functions?

The beta-endorphin residue of pituitary beta-lipotropin hormone, which regulates utilization and storage of body fat, is several times more potent than morphine in raising pain tolerance. It also produces habituation and dependency behavior. Recently it was found to be present in amniotic fluid and to be a releaser of prolactin. It now appears that the placenta is a rich source of endorphins. These findings may open a new chapter in understanding molecular determinants of behavior patterns responsible for natural selection and survival of vertebrate species. Clinical application of basic information and new concepts relating endorphins to maternal behavior patterns and neonatal physiology is the purpose of this communication. A brief review of the literature, some data from [3H]opiate-binding assays, observation of maternal performance, and reports of maternity patients' feelings and motivations suggesting that these hormone molecules mediate formation of affectional attitude, appetitive systems, and maternal behavior will be presented.