Biomaterial Database

The role of angiotensin II-stimulated renal tubular transport in hypertension. 2003

Kevin D Burns, and Ningjun Li

Division of Nephrology, The Ottawa Hospital and University of Ottawa, 1967 Riverside Drive, Room 535A, Ontario K1H 7W9, Canada. kburns@ottawahospital.on.ca

The kidney contains a renin-angiotensin system that appears to regulate systemic blood pressure. Angiotensin II (Ang II) has stimulatory effects on sodium transport in multiple nephron segments via binding to plasma membrane AT(1) receptors. In the proximal tubule, Ang II production is substantial. The stimulatory effect of Ang II on proximal sodium transport is enhanced by renal nerves, and is associated with internalization of apical and basolateral receptors. In the cortical collecting duct, AT(1) receptors stimulate transport through apical sodium channels, and in the inner medulla, urea transport is enhanced by Ang II, contributing to increased sodium and water reabsorption. AT(1) receptors may also be linked to increased expression of certain tubular sodium transporters. In contrast to the stimulatory effects of AT(1) receptors on sodium transport, AT(2) receptors expressed in the adult kidney are linked to increased urinary sodium excretion and decreased blood pressure. This suggests that renal tubular AT(1) receptor activation serves as a protective mechanism to increase sodium reabsorption and blood pressure when extracellular fluid volume is threatened, whereas AT(2) receptors dampen this response. The interplay between these two receptor pathways in the kidney could have significant effects on long-term blood pressure control.

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D007684	Kidney Tubules	Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.	Kidney Tubule,Tubule, Kidney,Tubules, Kidney
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
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
D015398	Signal Transduction	The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.	Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal