Postnatal Development of β-Endorphin-Related Peptides in Rat Anterior and Intermediate Pituitary Lobes: Evidence for Contrasting Development of Proopiomelanocortin Processing

摘要: The concentration of immunoreactive (ir-) β - endorphin (β-END) in the neurointermediate pituitary lobe was 15-fold higher adult than newborn rats; contrast, that ir-β -END anterior twice as high animals. Ir-β-END rats consisted exclusively (3-END-sized peptides, indicating at birth are capable processing opioid peptide precursor proopiomelanocortin (POMC) to -END. Moreover, -END-related peptides were found be predominantly α-Nacetylated and, therefore, inactivated with respect their opiate-like properties. Further analysis these α-N-acetylated forms on performance liquid chromatography indicated contained α-N-acetyl-(Ac-)β -END- (1-31), whereas major Ac-β (1-27) and -(1-26). Thus, C-terminal END-(1-31) -(1-27) -(1-26) may not yet f...