The systematic survey for novel vasoactive peptides produced in the adrenal medulla.

点击翻译按钮获取中文摘要

Mammalian circulation is regulated by subtle mechanisms involving several neural and hormonal factors. Several vasoactive peptides including angiotensin, ANP and endothelin are important regulators in the cardiovascular system. For clarifying the intricacies of circulation control, it is important to discover still unidentified vasoactive peptide.We discovered adrenomedullin in 1993 and found another hypetensive peptide proadrenomedullin N-terminal 20 peptide (PAMP) which is produced from adrenomedullin precursor. In this study, we performed systematic survey for isopeptide of adrenomedullin and PAMP. Using the RIA for the ring structure of adrenomedullin, we isolated and determined adrenomedullin (11-26) as endogenous peptide. The synthetic adrenomedullin (11-26) produced dose-dependent strong pressor responses in unanesthetized rats in vivo.Using a novel method to detect a peptide with C-terminal amide structure, we isolated a novel 14 amino acids peptide where C-terminus was amidated. This peptide was termed amidicin. Amidicin is widely distributed in porcine tissue and is especially abundant in pituitary gland, cardiac ventricle and spleen. Amidicin may be a possible new peptide participating in circulation control.