title: Isolation and identification of proangiotensin-12, a possible component of the renin-angiotensin system.
abstract: The renin-angiotensin (RA) system plays an important role in regulating blood pressure and fluid balance. In the search for bioactive peptides with an antibody binding to the N-terminal portion of angiotensin II (Ang II), we isolated a new angiotensinogen-derived peptide from the rat small intestine. Consisting of 12 amino acids, this peptide was termed proangiotensin-12 based on its possible role of an Ang II precursor. Proangiotensin-12 constricted aortic strips and, when infused intravenously, raised blood pressure in rats, while both the vasoconstrictor and pressor response to proangiotensin-12 were abolished by captopril and by CV-11974, an Ang II type I receptor blocker. Proangiotensin-12 is abundant in a wide range of organs and tissues including the small intestine, spleen, kidneys, and liver of rats. The identification of proangiotensin-12 suggests a processing cascade of the RA system, different from the cleavage of angiotensinogen to Ang I by renin.
authors.affiliation: Circulatory and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Nagata
authors.forename: Johji
authors.initials: J
authors.lastname: Kato
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sasaki
authors.forename: Naoto
authors.initials: N
authors.lastname: Minamino
authors.forename: Tanenao
authors.initials: T
authors.lastname: Eto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitamura
mesh_terms: D000595:Amino Acid Sequence; D000808:Angiotensinogen / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D012084:Renin-Angiotensin System / Q000502:physiology*; D014018:Tissue Distribution
chemical_list: D010446:Peptide Fragments; C515557:proangiotensin-12, rat; D000808:Angiotensinogen