Biomaterial Database

Angiotensin II and its heptapeptide (2-8), hexapeptide (3-8), and pentapeptide (4-8) metabolites in arterial and venous blood of man. 1976

P F Semple, and A S Boyd, and P M Dawes, and J J Morton

We made separate measurements of angiotensin II (A II) and of its immunoreactive metabolites (2-8 heptapeptide, 3-8 hexapeptide, and 4-8 pentapeptide) in arterial and venous plasma from subjects with widely different plasma levels of the peptides. A II and its three metabolites were extracted from blood, separated by paper chromatography, and measured by radioimmunoassay using an A II antiserum which had a 100% cross-reaction with each metabolite. In contrast to results of previous studies, A II was found to predominate in both arterial (60-100%) and venous (55-100%) blood. The biologically active 2-8 heptapeptide metabolite accounted for only 10% of the activity in arterial plasma. Radioimmunoassay of venous plasma extracts using an A II antiserum which had a low cross-reaction with the 3-8 hexapeptide and the 4-8 pentapeptide confirmed the results obtained using the antiserum which had a 100% cross-reaction with the metabolites. We conclude that radioimmunoassay methods for measuring A II in venous blood may be more accurate and relevant than has previously been recognized. The small difference between A II concentrations in arterial and venous plasma suggests further that there may be significant conversion of angiotensin I (A I) to A II in the limb vasculature.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D012083	Renin	A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.	Angiotensin-Forming Enzyme,Angiotensinogenase,Big Renin,Cryorenin,Inactive Renin,Pre-Prorenin,Preprorenin,Prorenin,Angiotensin Forming Enzyme,Pre Prorenin,Renin, Big,Renin, Inactive
D002854	Chromatography, Paper	An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).	Paper Chromatography,Chromatographies, Paper,Paper Chromatographies
D005260	Female		Females
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D006493	Heparin	A highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts.	Heparinic Acid,alpha-Heparin,Heparin Sodium,Liquaemin,Sodium Heparin,Unfractionated Heparin,Heparin, Sodium,Heparin, Unfractionated,alpha Heparin