Effects of endorphins and their analogues on prolactin and growth hormone secretion

Abstract

Following reports of the presence of endogenous opiate activity in brain (Hughes, 1975; Pasternak et al., 1975; Terenius et al., 1975), the pentapeptide Tyr-GlyGly-Phe-Met (met-enkephalin) has been isolated from porcine (Hughes et al., 1975) and calf (Simantov et al., 1976) brain. The sequence of this peptide is the same as the N-terminus of the C-fragment (ß-LPH_61-91), also called ß-lipotropin, first isolated from sheep pituitaries (Li et al., 1965). Both met-enkephalin and ß-endorphin have potent morphine-like activity (Chang et al., 1976; Hughes et al., 1975; Li et al., 1976a) and bind to the opiate receptor (Chang et al., 1976; Li et al., 1976b; Morin et al., 1976).