Biomaterial Database

Liver angiotensin II receptors in the rat: binding properties and regulation by dietary Na+ and angiotensin II. 1985

C Sernia, and L Sinton, and W G Thomas, and W Pascoe

Recent evidence suggests that angiotensin II (AII) acts on the liver via specific receptors. The aims of this study were to examine the general binding properties of these receptors in the rat and to determine the role of dietary Na+ and AII in the regulation of AII receptors. Binding of 125I-labelled Ile5-AII to liver membranes was saturable and behaved as a single class of sites with an affinity (Ka) of 2.9 l/nmol and a Hill coefficient of 0.99. Kinetic analysis of AII binding gave estimates for the rates of association and dissociation of 42 l/mumol per min and 1.5 X 10(-2)/min respectively. The binding of analogues exhibited the following order of potency: Val5-AII greater than Ile5-AII greater than AIII greater than Sar1-Ala8-AII greater than Sar1-Gly8-AII greater than AI greater than des-Asp-AI greater than C4-C8 pentapeptide greater than Phe1-Tyr8-AII greater than neurotensin greater than luteinizing hormone-releasing hormone. Binding was enhanced by Mg2+ and Ca2+ and inhibited by EDTA and the reducing agent dithiothreitol. Low dietary Na+ affected in a biphasic manner both the Ka and concentration (Ro) of liver AII receptors. Initially, Ro decreased from 25.9 +/- 3.8 (control) to 16 +/- 1.9 (S.E.M.) pmol/g tissue by 1.5 days but thereafter it rapidly increased to 47.3 +/- 8.7 pmol/g tissue (3.5 days) and remained elevated to the end of the experiment, 8.5 days later. The Ka initially increased from 2.7 +/- 0.3 (control) to 4.3 +/- 0.5 l/nmol (1.5 days) and then decreased steadily to 1.2 +/- 0.1 l/mol (8.5 days).(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D011869	Radioligand Assay	Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).	Protein-Binding Radioassay,Radioreceptor Assay,Assay, Radioligand,Assay, Radioreceptor,Assays, Radioligand,Assays, Radioreceptor,Protein Binding Radioassay,Protein-Binding Radioassays,Radioassay, Protein-Binding,Radioassays, Protein-Binding,Radioligand Assays,Radioreceptor Assays
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011945	Receptors, Angiotensin	Cell surface proteins that bind ANGIOTENSINS and trigger intracellular changes influencing the behavior of cells.	Angiotensin Receptor,Angiotensin Receptors,Angiotensin II Receptor,Angiotensin III Receptor,Receptor, Angiotensin II,Receptor, Angiotensin III,Receptor, Angiotensin
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D004039	Diet, Sodium-Restricted	A diet which contains very little sodium chloride. It is prescribed by some for hypertension and for edematous states. (Dorland, 27th ed)	Diet, Low-Salt,Diet, Low-Sodium,Diet, Salt-Free,Diet, Low Salt,Diet, Low Sodium,Diet, Salt Free,Diet, Sodium Restricted,Diets, Low-Salt,Diets, Low-Sodium,Diets, Salt-Free,Diets, Sodium-Restricted,Low-Salt Diet,Low-Salt Diets,Low-Sodium Diet,Low-Sodium Diets,Salt-Free Diet,Salt-Free Diets,Sodium-Restricted Diet,Sodium-Restricted Diets
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23